A cluster of isolates of Candida parapsilosis recovered from clinical specimens was demonstrated, by both classical and molecular epidemiological techniques, to have resulted from contamination in the laboratory. The source of the pseudoepidemic was a repeatedly utilized contaminated container of Hanks' balanced salt solution used in specimen processing. The patterns of restriction fragment length polymorphisms of DNA extracted from the clinical and environmental isolates were identical to each other but composed a newly identified unique C. parapsilosis DNA type.