The report describes the consequences of acute exposure to sulfolane upon the visual system, as measured using flash evoked potential (FEPs) and pattern reversal evoked potentials (PREPs). A single injection of either 1/2 or 1/4, but not 1/8 the i.p. LD50 (1600 mg/kg) produced significant increases in peak latencies of both FEPs and PREPs. These effects of sulfolane were apparent within 1 hour and lasted longer than 6 hours. In addition, sulfolane produced an ambient temperature- and dose-dependent hypothermia. Attenuating hypothermia eliminated the effects of sulfolane on latencies. Amplitudes of FEP peaks to the first of a pair of stimuli were generally increased compared to control, and this effect was probably not temperature dependent. Sulfolane, therefore, produces effects on the visual system, some of which are temperature dependent.