After 1950 it was observed an increase in the incidence of syphilis in the general population and this fact determined an investigation in order to evaluate the possible repercussion of this occurrence on the central nervous system, as an after effect of the elevated incidence. However, in this first study it was verified that there was a progressive and marked decrease of the neurosyphilis incidence in the 1936-1964 period, and that the frequency of meningovascular forms of the disease had increased lately in regard to the parenchymatous forms. The aim of the present work has been the continuation of this study after so many years. The material for this survey consisted of the clinical records of 148 patients picked out from 34.430 cases seen at the Neurological Department of Escola Paulista de Medicina (São Paulo, Brasil), during the 1962-1981 period, i. e., on twenty consecutive years. The results of this complementary investigation have shown instead that the incidence of neurosyphilis remained steady, changing very little every year, with an incidence at the rate of about 1:200. On the other hand, the frequency of the clinical forms of neurosyphilis changed very much. The usual forms such as general paresis and tabes are now scant and the observation of the uncommon forms, seldom seen in the past, is now progressively increasing through the years, so that they are the preponderant clinical forms today.