Cocaine hydrochloride (30, 15, or 0 mg/kg) was administered daily subcutaneously to male rats for a minimum of 72 days. Animals receiving the 15-mg/kg and 0-mg/kg doses were pair-fed with animals receiving the higher dose. A fourth group served as a nontreated ad libitum-fed control to assess the role of cocaine-associated decreases in food and water intake. Administration of cocaine resulted in dose-related decreases in body weights, increases in locomotor activity, and decreases in estradiol levels. The high dose of cocaine was also associated with an increase in the percentage of spermatozoa with heads separated from tails. Cocaine did not affect sexual behavior, relative weights of the testis or accessory organs, histology of the testis, number of implantations, resorptions, fetal or newborn weight of offspring, or offspring weight at 21 days of age but did result in hyperactivity and increased perseverance in a T maze.