Cisplatin is a chemotherapy drug that is widely used for treating various types of cancers. Oxidative stress may be a cause of cisplatin toxicity in male reproductive organs and, therefore, antioxidants might reduce the distractive effects of oxidative stress induced by cisplatin. The present study aimed to investigate the efficacy of Spirulina platensis, a microalga rich in antioxidant compounds, against cisplatin-induced oxidative damage. In this study, 30 male rats were divided into 3 groups as follows: 1) the control group (rats which received normal saline); 2) the cisplatin group (rats which received cisplatin, 5mg/kg BW); and 3) the spirulina+ cisplatin group (rats which received injections of cisplatin (5mg/kg BW) + 5% spirulina in the fed diet). After one month, the levels of reproductive hormones (testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH)) and antioxidant enzymes (glutathione: GSH, superoxide dismutase: SOD), and lipid peroxidation (malondialdehyde: MDA level) in the blood samples and also epididymal sperm parameters were tested in these three groups. Our results showed that FSH, LH, T, GSH, and SOD levels, as well as sperm count, motility, viability, and normal morphology, decreased, and the MDA amount increased in the cisplatin group compared with the control group. In the spirulina + cisplatin group, spirulina could compensate adverse effects of cisplatin compared with the cisplatin group. Spirulina with its antioxidant properties was able to reverse the negative effects of cisplatin and improve parameters involved in reproduction.