The clinical features, management and outcome of 178 early bleeding episodes into the musculature of the thigh and lower limb of 37 severe haemophiliacs are reported. Ninety-five per cent of all bleeds were treated in under three hours from onset of symptoms and the mean time to complete restoration of function was 3.5 days. The most frequent site of bleeding was the quadriceps (44 per cent) followed by the calf (35 per cent), anterior tibial compartment (seven per cent), adductors of the thigh (seven per cent), hamstrings (six per cent) and sartorius (one per cent). Bleeds of the quadriceps took longest to resolve (mean, four days), significantly longer than bleeds of the calf muscle (3.1 days). The first symptom in 66 per cent of bleeds was pain on movement. When the quadriceps was involved, this rapidly progressed to pain at rest. There was a significant prolongation of recovery time when bleeds of this muscle group were treated more than two hours after the onset of symptoms. Bleeds of the calf muscle required less transfusions and no prolongation in recovery time occurred in bleeds treated up to three hours from the onset of symptoms. The results of this study contrast markedly with earlier reports based on later presentations.