1. One hundred patients with paretic neurosyphilis were followed 6 months to 2 years after treatment. No significant difference was found in the results obtained with penicillin alone and with concurrent malaria-penicillin.2. Penicillin alone in a total dose of 6 million units within 30 days is of definite therapeutic value in paretic neurosyphilis.3. Nevertheless, until further experience is gained penicillin should be combined with malarial therapy in the treatment of paretic neurosyphilis.4. If for any reason fever therapy is contraindicated, penicillin alone is the best available method of treatment.