Thirteen pediatric patients with Crohn's disease, aged 12-22 yr, were studied to assess the prevalence of peripheral neuropathy due to oral metronidazole. After 4-11 mo of therapy, 11 of 13 patients (85%) had a sensory peripheral neuropathy, determined by abnormal neurologic examinations or reduced nerve conduction velocities, or both. Only 6 of the 11 patients were symptomatic. Nine of 11 patients with peripheral neuropathy had their metronidazole discontinued and 2 had the dose reduced to less than 10 mg/kg X day. Follow-up evaluations of the 9 patients whose metronidazole had been discontinued 5.5-13 mo earlier demonstrated complete resolution of the peripheral neuropathy in 5, improvement in 3, and no change in 1. In the 2 patients whose metronidazole dose was reduced, 1 showed worsening and 1 showed complete resolution of the neuropathy after 10-12 mo of continued therapy.