Impaired spermatogenesis and male infertility are common consequences of chemotherapy drugs used in patients with testicular cancer. The present study investigated the effects of sodium alginate (NaAL) on testicular toxicity caused by bleomycin, etoposide, and cisplatin (BEP). Rats in group 1 received normal saline, while groups 2 and 3 were treated with 25 and 50 mg/kg of NaAL, respectively. Group 4 was treated with a 21-day cycle of BEP (0.5 mg/kg bleomycin, 5 mg/kg etoposide, and 1 mg/kg cisplatin), and groups 5 and 6 received BEP regimen plus 25 and 50 mg/kg of NaAL, respectively. Then, sperm parameters, testosterone levels, testicular histopathology and stereological parameters, testicular levels of malondialdehyde (MDA), nitric oxide (NO), and total antioxidant capacity (TAC), and the expression of apoptosis-associated genes including Bcl2, Bax, Caspase3, p53, and TNF-α were evaluated. Our findings revealed that NaAL improved sperm parameters, testosterone levels, histopathology, and stereology parameters in BEP-administrated rats. NaAL also improved testis antioxidant status by enhancing TAC and ameliorating MDA and NO. Further, modifications to the expression of Bcl2, Bax, Caspase3, p53, and TNF-α suggested that NaAL alleviated BEP-induced apoptosis and inflammation. Collectively, NaAL protects rats’ testes against BEP-evoked toxicity damage through the modulation of nitro-oxidative stress, apoptosis, and inflammation.