Excited-state lifetimes and rotational reorientation times were obtained for trans-4,4'-diphenylstilbene (DPS) in a series of n-alkanes and nonalkane solvents as a function of temperature using picosecond time-resolved fluorescence lifetime and anisotropy measurements. The fluorescence lifetimes do not have a significant solvent or temperature dependence, indicating that isomerization via activated barrier crossing is not: a dominant decay pathway for S-1 DPS. However, the temperature dependence of the lifetime is shown to be larger in polar solvents than nonpolar solvents. Arrhenius plots for polar solvents give two different decay channels in the low-temperature and high-temperature regions. The rotational reorientation time of DPS is sensitive to solvent environments. In a given solvent the rotational reorientation times depend linearly on eta/T in agreement with the Debye-Stokes-Einstein theory. The data in n-alkane solvents show that the solute-solvent coupling, as evidenced by the friction coefficient, decreases as viscosity increases; in polar solvents, this trend appears to be reversed.