INTRODUCTION: Focal peripheral neuropathy of the median nerve is mainly caused by a traumatic event or pressure, but it may also be produced by systemic illnesses. Among the latter, leprosy is a rare cause. METHODS: Six cases of isolated median neuropathy as the first sign of leprosy were selected from patients with an exclusively neurological complaint as the initial symptom. The patients, evaluated at the National Leprosy Reference Center in Rio de Janeiro, Brazil, followed routine and specialized procedures. RESULTS: Three of the patients had pure neural leprosy, and 3 had skin lesions. Clinical median nerve function impairment was confirmed by neurophysiological testing and histopathology. Both mononeuritis and mononeuritis multiplex were observed. CONCLUSIONS: This case series demonstrates an additional form of presentation of leprosy, which, if not diagnosed and treated in time, may lead to permanent disability.