This study was designed to define the clinical utility of fungal blood cultures for human immunodeficiency virus type 1-infected individuals. A retrospective chart review was performed for all patients admitted to an inpatient AIDS unit who had evidence of an invasive fungal infection. During a 25-month period, 1,162 fungal blood cultures were performed for 322 patients. These cultures, along with bacterial blood cultures, resulted in the isolation of fungi from 26 patients; 15 of these isolates were considered true pathogens. Routine blood cultures were positive for the fungal isolates in all 15 cases: Candida species and Candida glabrata (6 cases), Cryptococcus neoformans (7), Coccidioides immitis (1), and Histoplasma capsulatum (1). All invasive fungal infections were diagnosed by other means before fungal blood cultures were reported as positive. The results of this study suggest that the routine performance of such cultures in clinical practice should be reevaluated.