Studies suggest Candida albicans infection has a negative effect on sperm function, including fertilizing ability. Assisted reproduction treatment using spermatozoa from a patient with unrecognized C. albicans infection did not result in fertilization. Preliminary evidence suggested an effect on sperm motility and apoptosis. This study was undertaken to evaluate the effects of experimentally induced C. albicans infection on motility, membrane mitochondrial potential (MMP), chromatin packaging and apoptosis [membrane phosphatidylserine (PS) externalization and DNA fragmentation] of spermatozoa isolated from normozoospermic healthy men. Motile spermatozoa were isolated by swim-up from 13 normal volunteers and exposed to increasing concentrations (0, 1000, 10,000, and 100,000 cfu/ml) of the fungus for 3 and 24 h. C. albicans was isolated from vaginal swabs, after identification, freshly prepared for experiments. Following incubation, sperm motility decreased significantly (P < 0.05 from 10,000 cfu/ml) and spermatozoa with reduced MMP or PS externalization, an early sign of apoptosis, increased in a time- and concentration-dependent manner. Sperm DNA fragmentation and chromatin integrity increased slightly after exposure to C. albicans, but the increase did not reach statistical significance. This study showed that C. albicans infection may decrease the functional competence of spermatozoa by reducing motility and MMP and by promoting molecular apoptosis mechanisms.