Relative rate constants for O-2(a(1) Delta g) radiative deactivation (k(Gamma)) have been determined in 19 solvents. The data ate consistent with earlier results that were obtained by using a different technique [Scurlock, R. D.; Ogilby, P. R. J. Phys. Chem. 1987, 91, 4599]. Of particular interest are the data in CS2, which heretofore had yet to be corroborated. Current results indicate that k(Gamma) for CS2 is indeed similar to 2 times larger than k(Gamma) for benzene. A compilation of these results, along with those of other investigators, is provided. Average values of k(Gamma) derived from this compilation correlate well with both the solvent refractive index and solvent polarizability. The data correlate less well with the solvent ionization potential. Possible mechanisms consistent with these data are discussed.