Photophysics and photochemistry of 2,2-diphenylhexamethyltrisilane (1) was investigated in detail. Diphenyltrisilane 1 showed an intense fluorescence band assignable to the intramolecular charge-transfer (ICT) band in a polar solvent. Whereas silylene extrusion and 1,3-silyl migration were the major photoreactions of 1 in a nonpolar solvent, solvolytic cleavage of the Si-Si bond occurred significantly in an ethanol-hexane mixture; the ICT state is responsible for the latter reaction. Solvent and temperature dependence of the product distribution has indicated that both the silylene extrusion and the 1,3-silyl migration take place from the nonpolar but electronically different excited states of 1. On the basis of the photoreactions of 1 using a nonresonant two-photon (NRTP) excitation method, it is suggested that the silylene extrusion occurs via the L-1(a) state of 1 as a silyl-substituted benzene.