In a retrospective review of microbiology records at the George Washington University Hospital from 1980 through 1990, Mycobacterium kansasii bacteremia was identified in 10 patients; this finding represented 4.5% of nontuberculous mycobacterial blood cultures. M. kansasii was isolated from respiratory specimens from all 10 patients, and pulmonary parenchymal changes were noted in five patients. The median survival time was 14 weeks; however, only five patients received therapy with two or more drugs active against M. kansasii.