Cat-scratch disease (CSD) is usually a self-limited illness, though atypical presentations of infection with Bartonella henselae can occur, including osteomyelitis, oculoglandular syndrome, and granulomatous hepatitis. We describe a 6-year-old boy who had atypical CSD osteomyelitis of the left proximal femoral metaphysis due to a cat scratch. This is the second paper to report serial serology of B henselae, and the second paper to identify plasma cells on histologic examination, compatible with chronic osteomyelitis. The diagnosis was made by clinical, serologic, and histologic examination. Sixteen cases of atypical CSD osteomyelitis have been reported in the English literature and are reviewed in this paper.