Ultrafast transient absorption measurements are reported for all-trans retinal in ethanol, hexane, and 3-methylpentane at temperatures from 85 K to room temperature. Investigation of the temperature dependence allows the mechanism of electronic relaxation and the presence of multiple conformers to be investigated. Relaxation of the initially excited B-1(u)+-like state of all-trans retinal in ethanol is detected by the decay of transient absorption at 550 nm and the decay of stimulated emission at 650 nm. The time constant for this component slows from 2 ps at room temperature to 420 ps at 85 K. The corresponding fluorescence quantum yields estimated from these decay times for the "B-1(u)+" state are sufficient to explain the measured fluorescence yields, suggesting that the fluorescence observed for all-transretinal in hydrogen-bonding solvents has its origin predominantly in the "B-1(u)+" state; The relaxation rate follows Arrhenius behavior at high temperatures but decreases less steeply at low temperature. The temperature dependence is consistent with internal conversion in the strong coupling limit. Tunneling contributions become evident at low temperatures. In contrast, the rate of intersystem crossing detected by the appearance of triplet-triplet absorption at 450 nm is independent of temperature, occurring in about 30 ps, However, the amplitude of the triplet-triplet absorption signal increases at low temperatures. These results demonstrate the presence of at least two distinct populations of retinal, which follow different relaxation channels at low temperature. Similar behavior is observed in hexane and 3-methylpentane, although the amplitude of the slow internal-conversion component is small.