Photophysical and photocatalytic properties of molybdates and tungstates with a scheelite structure were investigated. The band gaps of scheelite compounds narrowed when the compounds were composed of Ag+ and Bi3+ ions. (NaBi)(0.5)MoO4 (BG: 3.1 eV) and (AgBi)(0.5)MoO4 (BG: 3.0 eV) showed the photocatalytic activities for O-2 evolution from an aqueous solution containing an electron acceptor. On the other hand, (NaBi)(0.5)-WO4 (BG: 3.5 eV) produced H-2 from an aqueous solution containing an electron donor.