Haemarthroses in haemophiliacs can usually be limited by substituting the missing coagulation factor and are spontaneously reabsorbed within a few days. In rare cases, however, the blood remains inside the joint, leading to increasing destruction of the latter. This pathological development can be prevented right at the commencement phase by removing the effusion, which is generally in liquid form, by puncture, and the intraarticular clot by arthrotomy in good time. Experiences with this therapeutic concept, which can be described as "orthopedic early treatment of haemophilic haemarthrosis", are presented and discussed.