The aim of this study was to examine the protective effects of fish omega-3 (n-3) fatty acids on acute doxorubicin (DOX)-induced testicular apoptosis and oxidative damage. 24 male rats were divided into three groups: control, DOX-treated and DOX+fish n-3 fatty acids. Fish n-3 fatty acids (400 mg kg(-1)) were given for 30 days by intragastric gavage. The rats received a single intraperitoneal injection of DOX (30 mg kg(-1)) and were sacrificed after 48 h. The DOX+fish n-3 fatty acids group showed a decrease in malondialdehyde levels and increased activities of superoxide dismutase and glutathione peroxidase in comparison with the DOX-treated group. Acute DOX treatment caused severe damage such as disorganisation and separation of germ cells. The fish n-3 fatty acids-pretreated rats showed an improved histological appearance in the DOX-treated group. Our data indicate a reduction in the activity of terminal deoxynucleotidyl transferase mediated dUTP nick end labelling; there was a rise in the expression of proliferating cell nuclear antigen in testis tissues of the DOX+fish n-3 fatty acids group compared with DOX-treated group. These data suggested that fish n-3 fatty acids pre-treatment may be beneficial for spermatogenesis following acute DOX-induced testicular damage by decreasing germ cell apoptosis and oxidative stress.