Candida albicans is an increasingly important bloodstream pathogen. We investigated a cluster of bloodstream infections in the neonatal intensive care unit (NICU) to determine whether nosocomial transmission occurred. Subjects included any patient in the NICU who developed clinically significant bloodstream infection with C. albicans from January 1984 to December 1987 (N = 7). Isolates were typed by restriction fragment length polymorphism analysis using a C. albicans-specific DNA probe (27A). Four of the neonates were infected from June to August 1984 (1.4 infections per 100 admissions) (the epidemic period) versus none in the period from January to May 1984, and three in the period from September 1984 to December 1987 (0.12 infections per 100 admissions) (P = .002). Three of the four patients in the epidemic period were infected with identical strains, readily distinguished from epidemiologically unrelated strains from the NICU. We conclude that nosocomial transmission of C. albicans occurred and that neonates in intensive care units may represent one group at increased risk.