Disseminated mycobacterial disease due to Mycobacterium szulgai occurred in a previously healthy young man. The clinical picture included fever, mediastinal and generalized lymphadenopathy, hemoptysis, and skin lesions but was dominated by progressive multifocal osteomyelitis. Immunological studies revealed a decrease in T-lymphocyte reaction to mitogens, but this was tested late in the course of the disease and may have been secondary. In spite of repeated surgical drainage and treatment with multiple antituberculous drugs for a period of two years, new lesions continue to appear mainly in the bones. Mycobacterium szulgai was isolated from 28 bone specimens, as well as from skin lesions and sputum. To the best of our knowledge, this is the first report of disseminated disease due to this organism.