Congenital syphilis is a rare disease in central Europe. Placental changes may be non-specific but a typical finding is necrotizing funisitis of the umbilical cord. In a case report we describe how the histopathological incidental finding of B lymphocyte-rich, necrotizing funisitis led to the diagnosis of a previously unknown Treponema pallidum infection in parents and their newborn child. The pathological suspicion of congenital syphilis, although rare, has implications for the clinical management (serological evaluation of parents and child as well as the social environment, evaluation of viral coinfection and treatment decision) and is a notifiable disease.