A 33-y-old man with Hyper-IgM syndrome developed a severe tuberculous disease complicated by pleuritis and spondylitis. An abnormally decreased CD4/CD8 ratio, decreased CD4 + T-cell count and depressed natural killer cell activity implicated a coexistent cell-mediated immunodeficiency. To our knowledge, this is the first detailed report of tuberculosis associated with Hyper-IgM syndrome.