Syphilis is a re-emerging infectious disease in Western Europe. Congenital syphilis is a potentially serious pathology affecting newborns of infected mothers. This disease is easily curable by a simple antibiotic treatment. Because of systematic antenatal screening it should no longer exist in industrialized countries. Nevertheless, we report a case of a six-week-old infant with a delayed diagnosis of congenital syphilis. Physicians, especially gynaecologists, obstetricians and paediatricians, have to be vigilant in order to allow for early diagnosis and appropriate treatment of congenital syphilis.