Cisplatin, an anticancer drug used in chemotherapy, has made considerable progress recently; particularly in the treatment of testicular cancer. However, the side effects of this treatment, limit its use. Grape Seed and Skin Extract (GSSE) and Ulva rigida (U. rigida) marine seaweeds are giving compounds with high antioxidant capacity. This work aims to develop a model in vivo to evaluate the protective effect of extracts of GSSE or U. rigida against the oxidative stress induced by cisplatin. This stress occurring in healthy cells is one of the major causes of the adverse effects of chemotherapy. Healthy male rats received an intraperitoneal injection of cisplatin only or cisplatin and GSSE or U. rigida extract. At the end of the treatment, the rats were sacrificed and from the crushed testicles; the supernatant was recovered for biochemical assays. The data showed that the dose of cisplatin induces testicular toxicity, and a pro-oxidant state characterized by increased levels of malondialdehyde, carbonyl proteins, superoxide anion, calcium and iron. Besides, treatment with cisplatin increases the activity of superoxide dismutase and inhibits the activity of catalase. GSSE or U. rigida extract exerts a protective effect on the testes of cisplatin-treated rats, or they protect against the adverse effects of oxidative stress induced by cisplatin to restore levels near control. This study demonstrated that GSSE and U. rigida can protect against cisplatin-induced cytotoxicity.