During the Second World War and after the War venereal diseases (Syphilis and Gonorrhoea) were wide-spread. By a single census in October 1947 were notified 2960 syphilitic patients. In the years 1949-1951 intensive and effective preventive measures were introduced as compulsatory notification system of venereal diseases, sexual contact-tracing investigations, correct and rapid diagnosis of venereal diseases, rapid and efficient therapy of patients with syphilis, followup (post-treatment observations) for all patients, routine serological tests for syphilis, in expectant mothers at ante-natal clinics, periodical screening of high-risk groups, patients in each calendar year at their hospitalization, to taking up a post and a special drive against syphilis ("PN-action"). The results of these measures are manifested by substantial fall in the number of cases of syphilis and gonorrhoea. In the years 1948-1955 18,151 patients suffering from syphilis were notified. The changes of the incidence of syphilis and gonorrhoea are illustrated by statistical data (Tab. 1-9). Syphilis congenita occurs sporadicly, there is a substantial fall in the number of syphilitic pregnant. After 1989 there has been a greater group mobility and a substantial rise in active and passive tourisms and occupational travel activity, especially abroad. Changes of the sexual behaviour were expressed, especially a greater tolerance whether heterosexual or homosexual, sexual freedom, sexual promiscuity and especially prostitution.