Iliac osteomyelitis was diagnosed, in many cases after considerable delay, in twenty (2.3 per cent) of 867 children with hematogenous osteomyelitis. In ten patients coagulase-positive Staphylococcus aureus was identified. The symptoms and signs of iliac osteomyelitis depend on the direction of spread of the inflammation. The children presented with one of these syndromes: gluteal, abdominal, or lumbar disc. The diagnosis can be established early be careful physical examination: manual compression of the pelvis produces pain on the affected side, and palpation reveals tenderness over over the site of infection. The inflammatory process can be located even in early cases on a bone scan with radioactive technetium. When diagnosed early, the infection can be cured with intensive intravenous antibiotic therapy alone.