From January 1st up to September 30th 1990, 77 patients with leptospirosis confirmed by laboratory studies were admitted at the Infectious and Parasitic Diseases Service of the Hospital das Clínicas of the Universidade Federal de Pernambuco. Clinical manifestations had sudden onset with presence of fever, headache, chills and muscle pains. Plurisystemic involvement was observed both in the icteric and in the non-icteric patients. The neurological exam was abnormal in 70 of the patients (90.91%). Neurological findings were essentially variable. Though in a transitory form, they allowed the observation of the following clinical forms: meningoencephalitis and polyneuritis in association, meningoencephalitis, polyneuritis, and subarachnoid hemorrhage.