Acute primary infection of the epiphysis is uncommon. We present 2 cases of acute osteomyelitis of the distal femoral epiphysis. They were not diagnosed until 10 days and 3 weeks, respectively, after the onset of symptoms. The epiphyseal infection spread into the knee joint, and surgical debridement was performed. The majority of reported cases in the medical literature are of bacterial etiology, and the most common pathogen is Staphylococcus aureus. We report a rare case which was infected by Salmonella enteritidis. Prompt diagnosis and early treatment are required to prevent further destruction and growth disturbance.