To determine the value of somatosensory evoked potentials (SEP) testing in evaluating sensory deficit in stroke patients, we analyzed the relationship of their findings in 100 patients. SEP waveforms were obtained over the spine and scalp in response to tibial nerve stimulation at the ankle. Interside differences of latencies (P35, N42, P53), interside amplitude ratios (N42, P53) and the correlation coefficients (CC) were calculated. We used the CC to obtain a measure of similarity of responses to stimulation from opposite sides of the body. Evaluation of sensory deficit consisted of pinprick, touch, kinesthetic, cold, and vibration. Interside amplitude ratios and the CC of SEP correlated well with kinesthetic sense, but the former reflected the degree of sensory deficit more exactly. Latencies did not with all of sensations. We concluded that interside amplitude ratios of SEP were valuable for assessing clinical sensory deficit.