Objective Despite the presence of numerous tests of sperm quality and function, no single laboratory test can determine with accuracy and precision whether a man is fertile or not. It is important to evaluate the oxidative stress (OS) in male and female reproductive tracts especially because of the results have diagnostic and prognostic value in the management of infertility. A randomized double-blind controlled study was carried out on a total of 55 patients with primary male factor infertility in Maternity & Childhood Teaching Hospital. Methods The distributions of patients in group 1 were classified into eight subgroups according to pathological cause of infertility and 35 normal proven fertility volunteer men severed as a control group. Simvistatin (SIMLO) tablets (Ipca Laboratories Ltd. Mumbai, India) were given to all the patients, at dose of 20 mg twice per day for a period of 3 months. Seminal creatine kinase (CK) was assessed pre- and post-treatment. Results The results showed that high significant decrease (P < 0.05) of CK activity in asthenozoospermia, asthenoteratozoospermia, oligo asthenoteratozoospermia and teratozoospermia. While the most influence subgroup was in teratozoospermia that showed about 2.5-fold lower than pretreated patients. Conclusion This study suggests that simvistatin may be used as antioxidant treatment and CK assessment could be used as indirect index of OS in infertile patient.