Neurosyphilis (NS) has different clinical manifestations and can appear during any stage of syphilis. We aimed to identify the factors affecting poor outcome in NS patients. Patients with positive cerebrospinal fluid Venereal Disease Research Laboratory test, and positive serological serum treponemal or nontreponemal tests were classified as definite NS. The data of 141 patients with definite NS were submitted from 22 referral centers. Asymptomatic NS, syphilitic meningitis, meningovascular syphilis, tabes dorsalis, general paresis, and taboparesis were detected in 22 (15.6%), 67 (47.5%), 13 (9.2%), 10 (7%), 13 (9.2%), and 16 patients (11.3%), respectively. The number of HIV-positive patients was 43 (30.4%). The most common symptoms were headache (n = 55, 39%), fatigue (n = 52, 36.8%), and altered consciousness (50, 35.4%). Tabetic symptoms were detected in 28 (19.8%), paretic symptoms in 32 (22.6%), and vascular symptoms in 39 patients (27.6%). Eye involvement was detected in 19 of 80 patients (23.7%) who underwent eye examination and ear involvement was detected in eight of 25 patients (32%) who underwent ear examination. Crystallized penicillin was used in 109 (77.3%), procaine penicillin in seven (4.9%), ceftriaxone in 31 (21.9%), and doxycycline in five patients (3.5%). According to multivariate regression analysis, while headache was a protective factor in NS patients, double vision was significantly associated to poor outcome. We concluded that double vision indicated unfavorable outcome among NS patients. A high clinical suspicion is needed for the diagnosis NS. As determined in our study, the presence of headache in syphilitic patients can help in early diagnosis of central nervous system disease.