Male and female Long-Evans rats were treated with epichlorohydrin (ECH) by oral gavage (males: 12.5, 25, and 50 mg/kg/day; females: 25, 50, and 100 mg/kg/day) for 21 and 14 days, respectively, prior to mating trials with untreated animals. Treated females were further dosed until delivery. Fertility was assayed in the high-dose males only and was found to be totally impaired. No measured parameters of female reproduction were changed relative to controls. Treated males showed normal copulatory behavior. Sperm morphology and percentage motile sperm were not statistically different from control values in both ejaculated and cauda epididymal samples from ECH-treated animals. The number of sperm in ejaculates was normal while cauda epididymal sperm count was slightly decreased in males at the 50 mg ECH/kg dose level. Mean curvilinear velocity, straight-line velocity, and amplitude of lateral head displacement of cauda epididymal sperm were significantly reduced by ECH at 12.5 mg/kg/day and above. Sperm track linearity was also reduced, but only at 50 mg/kg/day. Beat/cross frequency of sperm was significantly increased at 12.5 mg/kg/day and above. All of the above sperm motion parameters showed dose-dependent trends. These effects are consistent with the spermatozoal metabolic lesions reported for alpha-chlorohydrin, a metabolite of ECH.