Nucleoside-induced neuropathy characteristically appears as a painful, symmetric, distal polyneuropathy. To evaluate the neurotoxic potential of zidovudine (ZDV, or azidothymidine), in persons with little confounding human immunodeficiency virus (HIV) neuropathy, we evaluated peripheral nerve function in persons completing placebo-controlled studies of ZDV in early HIV disease. Participants had been receiving placebo or ZDV at doses of 800-1,200 mg daily for a median 52 weeks at the time of evaluation. Neuropathic symptoms and abnormalities of motor and sensory function were present in fewer than 10% of both treatment groups. Depressed reflexes were found in 19% of the ZDV group and 18% of the placebo group. Quantitative sensory testing for vibration was abnormal in fewer than 10% of participants and the absolute scores favored the ZDV group. We thus found a low prevalence of peripheral nerve abnormalities and no evidence of ZDV neurotoxicity in this population.