A study has been carried out on photoluminescence (PL) and photoluminescence excitation (PLE) of unsensitized and reduction sensitized cubic and octahedral AgBr emulsions. It has been determined that the PL spectra of cubic and octahedral micro<?xpp hyph?>crystals differ. This difference is explained by the formation of polyhalogenoargentate complex anions (PHACA) during the synthesis of octahedral microcrystals. These PHACA adsorb on the microcrystal surface, resulting in appearance of PL bands which are not observed for cubic microcrystals. PHACA can be transformed, after capturing an electron from a reducing agent, into negatively charged fragments, which are efficient hole traps. It is found that Agl^-₂ and AgBrl^- complexes, which can be formed during the synthesis of nominally pure AgBr octahedral microcrystals, play an important role in reduction sensitization. The PLE spectra of the 550 and 590 nm PL bands, which appear upon reduction sensitization of octahedral AgBr microcrystals, have maxima at 3.75 and 2.80 eV for the 550 nm band and 3.81 and 2.88 eV for the 590 nm band. The energy difference between these PLE maxima corresponds to the energy of the spin-orbit splitting in the iodine atom ground state. This leads to the conclusion that the negatively charged fragments responsible for the 550 and 590 nm PL bands contain iodide ions. Finally, our results show that the AgBr emulsion PL consists not only of micro–crystal PL but also of the emission due to impurity centers formed in gelatin during synthesis of AgBr microcrystals.