Radioactive synoviorthesis, with (90)Y (knees) and (186)Rh (elbows and ankles) is a highly effective procedure that decreases both the frequency and the severity of recurrent intra-articular bleeds related to joint synovitis. The procedure should be performed as soon as possible to minimize the degree of articular cartilage damage, which based on many studies is irreversible. It can also be used in patients with inhibitors. On average, radioactive synoviorthesis has a 75-80% satisfactory outcome in the long-term. From the clinical standpoint, such efficacy can be measured by the decrease in the number of haemarthroses, with complete cessation for several years in some cases. One should bear in mind that in 20-25% of cases, radioactive synoviorthesis fails to control haemarthroses. In such cases, it can be repeated. Personal experience and the general recommendation among orthopaedic surgeons and haematologists is that when three early consecutive radioactive synoviortheses (repeated every three months) fail to halt synovitis, a surgical synovectomy (open or by arthroscopy) should be immediately considered.