The character of acute hematogenous osteomyelitis (AHO) in North American children has changed significantly during the past several decades. Although the typical clinical picture of established acute osteomyelitis in children (illness, dehydration, and an acutely painful limb) is still seen, more subtle presentations appear more frequently. Children often present with subacute osteomyelitis. Less common variants include Brodie's abscess, subacute epiphyseal osteomyelitis, and chronic recurrent multifocal osteomyelitis. Some patients present with a bone lesion that may be confused with other disease entities, including neoplasms. Biopsy is often needed to clarify the diagnosis. With the trend toward more invasive procedures in the neonatal intensive care unit, neonatal osteomyelitis is also seen more frequently. Advances in imaging technology, particularly improvements in technetium bone scanning and the advent of magnetic resonance imaging, have contributed to more precise diagnosis and better management of AHO. With the increased concern about medical economics, the recent trend toward decreasing the duration of intravenous antibiotic treatment of these infections appears to be appropriate as long as certain criteria are met. Neither surgery nor antibiotics alone will be associated with successful treatment in all cases, and this fact may explain the rare but continued morbidity that is still seen in children with AHO.