Sixty-two patients with symptomatic neurosyphilis were treated with 20 or 24 megaunits of intravenous penicillin G daily for 15 to 30 days. The mean follow-up time after the treatment was 30 months. Thirteen patients developed new neurological signs after the treatment. Their diagnosis were: general paresis (9), taboparesis (2), tabes dorsalis (1) and meningovascular neurosyphilis (1). After the treatment, thirty-six patients (58.1%) improved, 22 patients (35.5%) were unchanged and 4 patients (6.4%) deteriorated on clinical grounds. In two patients there was a progression to other forms of neurosyphilis. The results of the treatment of these patients with high doses of intravenous penicillin G were not different from the results verified with classical intramuscular penicillin that were reported in the literature, from the clinical standpoint.