Although cytotoxic chemotherapy is an effective method in the treatment of many types of cancer, it causes many side effects in the organism. One of these side effects is infertility in males. In this study, we aimed to evaluate testicular asymmetric dimethylarginine (ADMA), dimethylarginine dimethylaminohydrolase (DDHA), nitric oxide synthase (NOS) and testosterone levels in rats treated with cisplatin and to investigate the effect of DDHA/ADMA/NOS levels on testosterone level and spermatological parameters. For this purpose, 20 male Sprague Dawley rats aged 10-12 weeks and weighing 250-300 grams were used and the rats were divided into 2 groups. Control Group (n=10): No treatment was applied to the control group. Group 2; Cisplatin Group (n=10): Cisplatin was dissolved in normal saline at a dose of 5 mg/kg/ml and administered intraperitoneally as a single dose and the rats were decapitated after 7 days. In the cisplatin treated group, body weights (p<0.001), sperm motility (p=0.009), testicular (p=0.028), vesicular seminalis (p=0.001) and prostate weights (p=0.040), testicular DDAH1 (p=0.013) levels decreased; testicular ADMA (p=0.006) and testicular iNOS (p=0.002), levels increased. In conclusion, cisplatin administration affected ADMA, DDAH1, iNOS levels in the testis, which may be involved in endothelial dysfunction and thus may cause negative effects on spermatologic parameters.