Exhibit 13.1

CERTIFICATION

Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Pursuant to 18 U.S.C. § 1350, the undersigned officer of Bancolombia S.A. (the “Company”), hereby certifies, to such officer’s knowledge, that the Bank’s Annual Report on Form 20-F for the year ended December 31, 2017 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934 and that the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date:	April 29, 2018
		/s/  Juan Carlos Mora Uribe
		Name: Juan Carlos Mora Uribe Title:   Chief Executive Officer

The foregoing certification is being furnished solely pursuant to 18 U.S.C. § 1350 and is not being filed as part of the Report or as a separate disclosure document.