In the recent literature about neurosyphilis, several publications have mentioned more atypical presentations of neurosyphilis. Inadequate penicillin therapy and improved serological methods are supposed to be responsible for these findings. In contrast with this proposition the present retrospective study of two groups of neurosyphilitic patients (518 patients during the period 1930-1940 and 121 during 1970-1984) reveals no marked differences in clinical data of these groups. Besides the fall in incidence of syphilis and neurosyphilis and the shift in the male/female ratio, conforming to modern literature, there is an increase in the cases of asymptomatic neurosyphilis, due to development of the immunological techniques to detect the diagnosis 'neurosyphilis' earlier.