p-Hydroxyphenacyl (pHP) protected substrates have been shown to release the substrate including biologically important derivatives when photolyzed. In an effort to systematically explore the electronic effects of the leaving group on the efficacy of the photorelease, a series of pHP substituted benzoate esters with electron withdrawing and electron donating groups were synthesized and examined. The quantum yields, Stern-Volmer quenching rates, and reaction rates were determined. These results suggest that the leaving group nucleofugacity can influence the rate and efficiency of the photorelease process. The mechanistic details will be presented.