OBJECTIVE To investigate a method of chemical sterilization and its efficacy in adult albino rats. METHODS Evaluation was conducted 3 weeks after a single bilateral intratesticular injection of calcium chloride (CaCl2) at the dose of 5, 10, 15 or 20 mg per testis per 100 g body weight. RESULTS The significant graded diminution in relative sex organ weights, testicular androgenic enzymes like Delta5,3beta-hydroxysteroid dehydrogenase (Delta5,3beta-HSD) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and superoxide dismutase (SOD) activities, testicular content of reduced glutathione (GSH), plasma and intratesticular concentrations of testosterone, epididymal sperm count as well as significant elevation in plasma concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testicular content of malondialdehyde (MDA) were noted in all the treated groups with respect to vehicle control. There was no chronic general stress in experimental animals as indicated by insignificant changes in plasma concentrations of corticosterone, prolactin, total protein, blood urea nitrogen and fasting blood sugar level. Dose-dependent responses on testicular histopathology were recorded by noting multinucleated giant cells in seminiferous tubules, derangement of tubular architecture along with infiltration of leucocytes and appearance of fibrous tissue throughout the testicular sections. The fertility efficacy of the 10, 15 or 20 mg CaCl2-treated males was nil, proven after mating with fertile, virgin healthy females, as there were no implantation sites in each uterine horns noted by laparotomy. CONCLUSIONS Intratesticular CaCl2 injection at a specific dose might serve as a way of sterilization and may be considered as an alternative to surgical castration in male animals.