In 1977 Brackmann for the first time reported an induction of tolerance in hemophiliacs with inhibitors using a protocol requiring administration of very high daily doses of factor VIII and activated prothrombin complex concentrates. Since the costs of such a protocol are enormous, we report our experiences in 3 hemophiliac children with inhibitors against factor VIII treated with much lower doses of factor VIII concentrate only for induction of tolerance. Two "high responder" and one "low responder" initially for only a short period received factor VIII concentrate in doses comparable to the Brackmann protocol. After that period patients were treated with 25--30 units factor VIII concentrate/kg/day, doses that are comparable to conventional prophylactic treatment. In one high responder the inhibitor disappeared completely after 22 months, in the other high responder the inhibitor titer decreased from 133 BU to 4.4 BU. In the low responder also a significant decrease of the inhibitor titer was observed. At this time bleedings in all three patients can be controlled by conventional doses of factor VIII concentrate.