Two well characterized photosensitizers, namely, 4-m-methoxy-p-hydroxy benzylidene-2-m-methoxy-p-hydroxystyryl-1-phenyl-2-imidazolin-5-one (subsequently referred to as 2-imidazolin-5-one) and Rose Bengal, have been used together to sensitize sprayed ZnO thin film electrodes in aqueous and acetonitrile media. Through current-potential curves and action spectra (i(photo)/lambda), it has been confirmed that both dyes, when present together, contribute additively to the sensitized photocurrent. The quantum efficiencies of the;dye-sensitized photocurrent at 480 and 555 nm wavelengths (lambda(max) of 2-imidazolin-5-one and Rose Bengal, respectively) were found to be 3.5 and 4.4%, respectively, in aqueous solution, while in acetonitrile medium the corresponding values were 4 and 6.5%.