EXHIBIT 21.1

Subsidiaries of United Surgical Partners International, Inc.

25 East Same Day Surgery, L.L.C.

Advanced Ambulatory Surgical Care, L.P.

Adventist Midwest Health/USP Surgery Centers, L.L.C.

Alamo Heights Surgicare, L.P.

Alexandria Surgery Center Real Estate, LLC

ALMH Surgical Center East, LLC

American Endoscopy Services, LLC

Arlington Surgicare Partners, Ltd.

Aspen Healthcare Holdings, Ltd.

Aspen Healthcare, Ltd.

Aspen Leasing, Ltd.

Austintown Surgery Center, LLC

Baptist Plaza Surgicare, L.P.

Baptist Surgery Center, L.P.

Bagley Holdings, LLC

Baylor Surgicare at Plano, LLC

Beaumont Surgical Affiliates, Ltd.

Bellaire Outpatient Surgery Center, L.L.P.

Bon Secours Surgery Center at Harbour View, LLC

Bon Secours Surgery Center at Virginia Beach, LLC

Briarcliff Ambulatory Surgery Center, L.P.

Cape Surgery Center, L.P.

Cedar Park Surgery Center, L.L.P.

Central Avenue Surgery Center, LLC

Central Jersey Surgery Center, LLC

Central Virginia Surgi-Center, L.P.

CHC/USP Surgery Centers, LLC

Chesterfield Ambulatory Surgery Center, L.P.

Chico Surgery Center, LP

Christus Cabrini Surgery Center, L.L.C.

Christus Santa Rosa Surgery Center, L.L.P.

Christus/USP General Partner, LLC

Christus/USP Surgery Centers, L.P.

CHW/USP Glendale GP, LLC

CHW/USP Glendale Memorial Surgery Centers, L.L.C.

CHW/USP Folsom GP, LLC

CHW/USP Fontana Surgery Centers, LLC

CHW/USP Las Vegas Surgery Centers, LLC

CHW/USP Oxnard GP, LLC

CHW/USP Oxnard Surgery Centers, LLC

CHW/USP Phoenix II, LLC

CHW/USP Roseville GP, LLC

CHW/USP Sacramento Surgery Centers, L.L.C.

CHW/USP San Gabriel GP, L.L.C.

CHW/USP San Gabriel Surgery Centers, L.L.C.

CHW/USP Surgery Centers, LLC

Clarkston ASC Partners, LLC

Coast Surgery Center, L.P.

Corpus Christi Holdings, LLC

Corpus Christi Surgicare, Ltd.

Corral Hollow Surgery Center, LLC

Court Street Surgery Center, L.P.

Creekwood Surgery Center, L.P.

CS/USP General Partners, LLC

CS/USP Surgery Centers, LP

Dallas Surgical Partners, L.L.P.

Day-Op Surgery Consulting Company, LLC

Decatur Surgery Center, L.P.

Denton Surgicare Partners, Ltd.

Denton Surgicare Real Estate, Ltd.

Desert Ridge Outpatient Surgery, LLC

Desoto Surgicare Partners, Ltd.

Destin Surgery Center, Ltd.

Doctors Outpatient Surgicenter, Ltd.

Doctors Surgery Center of Kingman, L.L.C.

East Brunswick Surgery Center, LLC

East West Surgery Center, L.P.

Eastgate Building Center, L.L.C.

Einstein/USP General Partner, LLC

Elmwood Park Same Day Surgery, L.L.C.

ENH/USP Surgery Centers I, L.L.C.

ENH/USP Surgery Centers II, L.L.C.

Folsom Outpatient Surgery Center, L.P.

Fort Worth Osteopathic Surgery Center, L.P.

Fort Worth Osteopathic Surgery Center GP, L.L.C.

Fort Worth Surgicare Partners, Ltd.

Frisco Medical Center, L.L.P.

Frontenac Ambulatory Surgery & Spine Care Center, L.P.

Garland Surgicare Partners, Ltd.

Georgia Musculoskeletal Network, Inc.

Genesis ASC Partners, LLC

Glendale Memorial Ambulatory Surgery Center, L.P.

Global Healthcare Partners, Ltd.

GP Surgery Center, LLC

Grapevine Surgicare Partners, Ltd.

Greater Baton Rouge Surgical Hospital, LLC

Health Horizons of Kansas City, Inc.

Health Horizons of Murfreesboro, Inc.

Health Horizons of Nashville, Inc.

Highgate Private Clinic, Ltd.

Hinsdale Surgical Center, LLC

Huguley Surgery Center, LLP

INTEGRIS/USP Surgery Centers, LLC

INTEGRIS/USP Surgery Centers II, L.L.C.

Idaho Surgery Center, LLC

Irving-Coppell Surgical Hospital, L.L.P.

ISS-Orlando, LLC

KSF Orthopaedic Surgery Center, L.L.P.

Lake County Ambulatory Surgery Center, LLC

Lake Lansing ASC Partners, LLC

Lansing ASC Partners, LLC

Las Cruces Surgical Center LLC

Lawrenceville Surgery Center, L.L.C.

Lewisville Surgicare Partners, Ltd.

Liberty Ambulatory Surgery Center, L.P.

Lincolnwood Ambulatory Surgery Center, L.P.

Madison Ambulatory Surgery Center, LLC

Manchester Ambulatory Surgery Center, LP

Manitowoc Surgery Center, LLC

Mary Immaculate Ambulatory Surgery Center, LLC

Mason Ridge Ambulatory Surgery Center, L.P.

McLaren ASC of Flint, LLC

McLaren Real Estate Partners, Limited Partnership

MCSH Real Estate Investors, Ltd.

Medcenter Management Services, Inc.

Memorial Ambulatory Surgery Center, LLC

Memorial Hermann Specialty Hospital Kingwood, L.L.C.

Memorial Hermann Surgery Center Cy-Fair, LLP

Memorial Hermann Surgery Center Katy, LLP

Memorial Hermann Surgery Center Northwest LLP

Memorial Hermann Surgery Center Pearland, LLP

Memorial Hermann Surgery Center Southwest, L.L.P.

Memorial Hermann Surgery Center Texas Medical Center, LLP

Memorial Hermann Surgery Center Sugar Land, L.L.P.

Memorial Hermann Surgery Center — The Woodlands, LLP

Memorial Hermann Surgery Center Westside, LLP

Memorial Hermann/USP Surgery Centers, LLP

Memorial Hermann/USP Surgery Centers II, LP

Memorial Hermann/USP Surgery Centers III, LLP

Memorial Hermann/USP Surgery Centers IV, LLP

Mercy/USP General Partners, L.L.C.

Mercy/USP Surgery Centers, L.P.

Metro Surgery Center, L.P.

Metroplex Surgicare Partners, Ltd.

MH/USP Kingwood, LLC

Michigan ASC Partners, L.L.C.

Mid Rivers Ambulatory Surgery Center, L.P.

Middle Tennessee Ambulatory Surgery Center, L.P.

Mountain Empire Surgery Center, L.P.

MSH Partners, LLP

New Horizons Surgery Center, LLC

New Mexico Orthopaedic Surgery Center Limited Partnership

North MacArthur Surgery Center, LLC

North Central Surgical Center, L.L.P.

North Garland Surgery Center, L.L.P.

North Shore Same Day Surgery, L.L.C.

NKCH/USP Surgery Centers, LLC

NKCH/USP Surgery Centers II, L.L.C.

NKCH/USP Briarcliff GP, LLC

NKCH/USP Liberty GP, LLC

Northeast Ohio Surgery Center, LLC

Northern Monmouth Regional Surgery Center, L.L.C.

Northridge Surgery Center, L.P.

Northside-Cherokee/USP Surgery Centers, L.L.C.

Northwest Georgia Orthopaedic Surgery Center, LLC

Northwest Surgery Center, Ltd.

Northwest Surgery Center, LLP

Oklahoma Center for Orthopedic and Multi-Specialty Surgery, LLC

Olive Ambulatory Surgery Center, L.P.

Opthalmology Anesthesia Services, LLC

Orlando Opthalmology Real Estate Investors, LLC

Orlando Opthalmology Surgery Center, LLC

Ortho Excel, Inc.

OrthoLink ASC Corporation

OrthoLink Baptist ASC, LLC

OrthoLink Physicians Corporation

OrthoLink Radiology Services Corporation

OrthoLink/ Georgia ASC, Inc.

OrthoLInk/New Mexico ASC, Inc.

OrthoLink/TN ASC, Inc.

OrthoLInk/TOC, LLC

Orthopedic and Surgical Specialty Company, LLC

Orthopedic South Surgical Partners, LLC

Pacific Endo-Surgical Center, L.P.

Park Cities Surgery Center, L.P.

Park Cities/Trophy Club GP, LLC

Parkway Surgery Center, LLC

Parkwest Surgery Center, L.P.

Pasadena Holdings, LLC

Pearland Ambulatory Surgery Center, Ltd.

Physicians Data Professionals, Inc.

Physicians Pavilion, L.P.

Physicians Surgery Center of Tempe, LLC

Physicians Surgical Center of Ft. Worth, LLP

Providence/USP Santa Clarita GP, LLC

Providence/USP Surgery Centers, L.L.C.

Radsource, LLC

Reading Ambulatory Surgery Center, L.P.

Redmond Surgery Center, LLC

Resurgens Surgery Center, LLC

Richmond ASC Leasing Company, LLC

River North Same Day Surgery, L.L.C.

Riverside Ambulatory Surgery Center, L.P.

Rockwall Ambulatory Surgery Center, L.L.P.

Rockwall/Heath Surgery Center, L.L.P.

Roseville Surgery Center, L.P.

Roswell Surgery Center, L.L.C.

Saint Thomas Campus Surgicare, L.P.

Saint Thomas/USP — Baptist Plaza, L.L.C.

Saint Thomas/USP Surgery Centers, L.L.C.

Saint Thomas/USP Surgery Centers II, LLC

Same Day Surgery, LLC

Same Day Management, L.L.C.

San Antonio Endoscopy, L.P.

San Fernando Valley Surgery Center, L.P.

San Gabriel Ambulatory Surgery Center, L.P.

San Gabriel Valley Surgical Center, L.P.

San Martin Surgery Center, LLC

Sand Lake Surgery Center, L.P.

Santa Clarita Surgery Center, L.P.

Sarasota Surgicare, Ltd.

Scripps Encinitas Surgery Center, LLC

Scripps/USP Surgery Centers, L.L.C.

Shrewsbury Surgery Center, LLC

Shore Outpatient Surgicenter, L.L.C.

Shoreline Real Estate Partnership, LLP

Shoreline Surgery Center, LLP

SmartHealth Norwin Hills Outpatient Center, L.P.

Southwest Ambulatory Surgery Center, L.L.C.

Specialists Surgery Center, L.L.C.

Specialty Lithotripsy Services, LLC

Specialty Surgicenters, Inc.

SSI Holdings, Inc.

St. Agnes Surgery Center of Ellicott City, L.L.L.P.

St. Agnes/USP Joint Venture, LLC

St. John’s Outpatient Surgery Center, LP

St. Joseph’s Outpatient Surgery Center, LLC

St. Mary’s Ambulatory Surgery Center, LLC

St. Mary’s Surgical Center, LLC

St. Mary’s/USP Surgery Centers, LLC

St. Vincent Health/USP, LLC

Sugar Land Surgical Hospital, LLP

Summit Radiology, LLC

Sunset Hills Ambulatory Surgery Center, L.P.

Suburban Endoscopy Services, LLC

Surgery Center of Canfield, LLC

Surgery Center of Columbia, L.P.

Surgery Center of Georgia, LLC

Surgery Center of Gilbert, LLC

Surgery Center of Peoria, LLC

Surgery Center of Scottsdale, LLC

Surgery Centers Holdings Company, L.L.C.

Surgery Centers of America II, LLC

Surgicoe of Texas, Inc.

Surgicoe Real Estate, L.L.C.

Surginet, Inc.

Surginet of Northwest Houston, Inc.

Surgis, Inc.

Surgis Management Services, Inc.

Surgis of Chico, Inc.

Surgis of Pearland, Inc.

Surgis of Phoenix, Inc.

Surgis of Redding, Inc.

Surgis of Rivergate, Inc.

Surgis of Sand Lake, Inc.

Surgis of Sonama, Inc.

Surgis of Victoria, Inc.

Surgis of Willowbrook, Inc.

Tamarac Surgery Center LLC

Templeton Surgery Center, LLC

Terre Haute Surgical Center, LLC

Teton Outpatient Services, LLC

Texan Ambulatory Surgery Center, L.P.

Texas Health Venture Arlington L.P.

Texas Health Venture Bellaire, L.P.

Texas Health Venture Denton L.P.

Texas Health Venture DSP L.P.

Texas Health Venture Fort Worth, L.L.C.

Texas Health Venture Frisco, L.P.

Texas Health Venture Garland, L.P.

Texas Health Venture Grapevine L.P.

Texas Health Venture Huguley, L.P.

Texas Health Venture Irving-Coppell, L.P.

Texas Health Venture North Garland, L.P.

Texas Health Venture Park Cities, L.P.

Texas Health Venture Park Cities/Trophy Club, LP

Texas Health Venture Plano, LLC

Texas Health Venture Rockwall, L.P.

Texas Health Venture Rockwall 2, L.P.

Texas Health Ventures Group L.L.C.

Texas Health Ventures Group Holdings, LLC

The Ambulatory Surgical Center of St. Louis, L.P.

The Center for Ambulatory Surgical Treatment, L.P.

The Surgery Center, an Ohio limited partnership

THVG Arlington GP, LLC

THVG Bedford GP, LLC

THVG Bedford, L.P.

THVG Bellaire GP, LLC

THVG Denton GP, LLC

THVG DeSoto GP, LLC

THVG DeSoto, L.P.

THVG DSP GP, LLC

THVG Fort Worth GP, LLC

THVG Fort Worth, L.P.

THVG Frisco GP, LLC

THVG Garland GP, LLC

THVG Grapevine GP, LLC

THVG Huguley GP, LLC

THVG Irving-Coppell GP, LLC

THVG Lewisville GP, LLC

THVG Lewisville, L.P.

THVG North Garland GP, LLC

THVG Park Cities GP, LLC

THVG Park Cities/Trophy Club GP, LLC

THVG Rockwall GP, LLC

THVG Rockwall 2 GP, LLC

THVG Valley View GP, LLC

THVG Valley View L.P.

THVG/HeatlhFirst, LLC

THVG/HealthFirst Holdings, LLC

Toms River Surgery Center, L.L.C.

TOPS Specialty Hospital, Ltd.

Trophy Club Medical Center, L.P.

Tulsa Outpatient Surgery Center, LLC

United Surgery Center — Southeast, Ltd.

United Surgical Associates, L.L.C.

University Surgical Partners of Dallas, L.L.P.

United Surgical of Atlanta, Inc.

United Surgical Partners Holdings, Inc.

University Surgery Center, Ltd.

USP Alexandria, Inc.

USP Assurance Company

USP Austin, Inc.

USP Austintown, Inc.

USP Baton Rouge, Inc.

USP Baltimore, Inc.

USP Bridgeton, Inc.

USP Cedar Park, Inc.

USP Central New Jersey, Inc.

USP Chesterfield, Inc.

USP Chicago, Inc.

USP Cleveland, Inc.

USP Coast, Inc.

USP Columbia, Inc.

USP Corpus Christi, Inc.

USP Cottonwood, Inc.

USP Creve Coeur, Inc.

USP Decatur, Inc.

USP Des Peres, Inc.

USP Destin, Inc.

USP Domestic Holdings, Inc.

USP Florissant, Inc.

USP Fredericksburg, Inc.

USP Frontenac, Inc.

USP Glendale, Inc.

USP Harbour View, Inc.

USP Houston, Inc.

USP Indiana, Inc.

USP International Holdings, Inc.

USP Kansas City, Inc.

USP Knoxville, Inc.

USP Las Cruses, Inc.

USP Long Island, Inc.

USP Lyndhurst, Inc.

USP Mason Ridge, Inc.

USP Michigan, Inc.

USP Midwest, Inc.

USP Mission Hills, Inc.

USP Nevada, Inc.

USP Nevada Holdings, LLC

USP Newport News, Inc.

USP New Jersey, Inc.

USP North Kansas City, Inc.

USP North Texas, Inc.

USP Oklahoma, Inc.

USP Olive, Inc.

USP Oxnard, Inc.

USP Philadelphia, Inc.

USP Phoenix, Inc.

USP Reading, Inc.

USP Richmond, Inc.

USP Richmond II, Inc.

USP Sacramento, Inc.

USP San Antonio, Inc.

USP San Gabriel, Inc.

USP Sarasota, Inc.

USP Securities Corporation

USP St. Peters, Inc.

USP Sunset Hills, Inc.

USP Tennessee, Inc.

USP Texas, L.P.

USP Texas Air, L.L.C.

USP Torrance, Inc.

USP Virginia Beach, Inc.

USP Webster Groves, Inc.

USP West Covina, Inc.

USP Westwood, Inc.

USP Winter Park, Inc.

USPE Holdings Limited

USPI San Diego, Inc.

Utica ASC Partners, LLC

Valley View Surgicare Partners, Ltd.

Victoria Ambulatory Surgery Center, LP

Warner Park Surgery Center, LP

Webster Ambulatory Surgery Center, L.P.

West Houston Ambulatory Surgical Associates, L.P.

Willowbrook Ambulatory Surgery Center, L.P.