Bacterial osteomyelitis in children must be diagnosed quickly and requires immediate and adequate antibiotic treatment. Surgical interventions may be necessary. Infants as well as immunodeficient patients suffer more often from hematogenic bone infections than immunocompetent patients. According to recent findings, autoinflammatory nonbacterial osteitis is more probable in immunocompetent patients in good general condition and should always be considered as a differential diagnosis. Diagnostic and therapeutic approaches are presented when childhood osteomyelitis is suspected.