X0202 4 2006-05-01 0 0001144215 ACUITY BRANDS INC AYI 0001183385 WILLIAMS NEIL C/O ACUITY BRANDS, INC. 1170 PEACHTREE STREET, NESUITE 2400 ATLANTA GA 30309 1 0 0 0 Stock Units 2006-05-01 4 A 0 212 41.34 A Common Stock 212 15388 D Stock Units are accrued under the Issuer's Nonemployee Directors' Deferred Stock Unit Plan and are payable in cash upon retirement in either lump sum or five annual installments. Accruals include required and elective deferral of director fees and reinvestment of dividend equivalents. During the Reporting Period, dividends earned and fees paid to the Reporting Person resulted in an increase in the number of units held. 1-for-1 Stock Units issued pursuant to the Plan are payable in cash upon retirement in either a lump sum or five annual installments. Neil Williams 2006-05-03