A 31-year-old man was found to have a diffuse infection of the wrist and osteomyelitis of the scaphoid caused by Mycobacterium kansasii. The 3-year delay in establishing the diagnosis is characteristic of hand infections caused by atypical mycobacteria. We treated the patient surgically and with antituberculous chemotherapy. This is the only case of M. kansasii osteomyelitis of the scaphoid recorded in the medical literature.