261 out of 336 845 blood donors have been shown to had undergone a syphilitic infection. About 52 per cent of these donors have had knowledge of their infection and of specific treatment of the disease. In about 43 per cent of the investigated cases the T. pallidum infection has had probably an inapparent course and healed without treatment, that means spontaneously. In times with an increasing number of infections by T. pallidum blood banks have to look intensively for donors which are in the first stage of primary syphilis. For identification of these people and for the differentiation between antibodies against T. pallidum and apathogenic treponemes the use of a TPHA-ABS test is discussed.