Acute pyogenic osteomyelitis in children continues to be a problem in orthopaedics. The causes of acute hematogenous osteomyelitis are not adequately known, but the histologic progression of the disease has been described. Early diagnosis with culture of an aspiration specimen is of paramount importance. Treatment with antibiotic agents is often successful unless pus is obtained on aspiration. In patients with an established abscess, surgical drainage is often required in addition to antibiotic therapy. Oral antibiotics appear to be as effective as parenteral antibiotics, provided adequate serum bactericidal titers can be demonstrated. Staphylococcus aureus is the most common causative organism, although other organisms are often found in special circumstances, such as in neonates, patients with sickle-cell disease, and those with puncture wounds of the foot.