Seventy patients with antemortem fungemia were studied. The findings and subsequent course of the patients allowed these episodes of fungemia to be related to disseminated fungal infection (44 patients), transient catheter-induced fungemia (8 patients), or clinically insignificant fungemia (18 patients). Candida fungemias were associated with disseminated mycosis when the patients were immunosuppressed, leukopenic, grew Candida organisms from three or more other sites, or did not have a contaminated intravenous catheter. Noncandida fungemias were associated with disseminated fungal infection when the patients had multiple other positive sites, grew fungus out of more than one blood culture, and had fungemias with recognized pathogens. Sixty-three percent of the patients had either autopsy-proved or clinically diagnosed disseminated mycoses. Fungemia in patients with compromised host resistance, especially lymphoreticular or hematopoietic malignancies, is frequently associated with disseminated fungal infection.