[en] Sexually transmitted diseases (STD) show frequent epidemiological changes. We report a case of secondary syphilis diagnosed in a 32-year old woman during post-partum. The disease, although showing a typical presentation, raises the problem of dating with precision the contamination time. This is of importance for treating the newborn at risk of congenital syphilis. We highlight the constant attention that should be brought to disclose this venereal disease that shows so variable clinical and histological presentations. Syphilis seems on the rise in the Mosan valley and in some cities where prostitution is imported from Eastern Europe and Africa.