Of 89 consecutive patients undergoing treatment for hematologic malignancies or undergoing allogeneic bone marrow transplantation, 60 were colonized with Candida albicans and 25 with C. tropicalis. However, of the 18 disseminated infections caused by Candida species, 15 infections in 14 patients were caused by C. tropicalis and only three infections in three patients by C. albicans. The setting in which the infection occurred, skin lesions, polyarthralgias, or polymyalgias, and the unexplained deterioration of renal function were features suggestive of the diagnosis. Defervescence occurred in 10 of the 14 treated patients with C. tropicalis infections in 1 to 6 d (mean, 2.5 d) after initiation of therapy, even though all continued to be granulocytopenic. Resolution occurred in eight of the 15 C. tropicalis infections. In one case outcome was indeterminate, four patients died due to the infection, and two died from other causes but with the infection unresolved.