Photochemical properties of photoinduced omega-bond dissociation in p-benzoylbenzyl phenyl sulfide (BBPS) in solution were investigated by time-resolved EPR and laser flash photolysis techniques. BBPS was shown to undergo photoinduced omega-bond cleavage to yield the p-benzoylbenzyl radical (BBR) and phenyl thiyl radical (PTR) at room temperature. The quantum yield (Phi(rad)) for the radical formation was found to depend on the excitation wavelength, i.e., on the excitation to the excited singlet states, S-2 and S-1 of BBPS; Phi(rad)(S-2) = 0.65 and Phi(rad)(SI) = 1.0. Based on the CIDEP data, these radicals were found to be produced via the triplet state independent of excitation wavelength. By using triplet sensitization of xanthone, the efficiency (alpha(rad)) of the C-S bond fission in the lowest triplet state (T-1) of BBPS was determined to be unity. The agreement between Phi(rad)(SI) and alpha(rad) values indicates that the C-S bond dissociation occurs in the T-1 state via the S, state due to a fast intersystem crossing from the S-1 to the T-1 state. In contrast, the wavelength dependence of the radical yields was interpreted in terms of the C-S bond cleavage in the S-2 state competing with internal conversion from the S-2 to the S-1 state. The smaller value of Phi(rad)(S-2) than that of Phi(rad)(S-1) was proposed to originate from the geminate recombination of singlet radical pairs produced by the bond dissociation via the S-2 state. Considering the electronic character of the excited and dissociative states in BBPS showed a schematic energy diagram for the omega-bond dissociation of BBPS.