There are some studies regarding the presence/absence of oxidative stress in patients with hypogonadism with limited number of parameters. We aimed to investigate the effects of male hypogonadism and its treatment on oxidative stress parameters. Thirteen male patients with hypogonadotropic hypogonadism and 20 healthy subjects were involved in the study. Patients with hypogonadism were evaluated before and after six months of therapy. Markers indicating lipid and protein oxidation, total oxidant status (TOS) and total anti-oxidant capacity (TAC) were evaluated. Control subjects had significantly higher serum testosterone levels in comparison to hypogonadal patients before the treatment period. After the treatment of hypogonadism serum testosterone levels increased significantly. Myeloperoxidase (MPO) activity, levels of advanced oxidation protein products (AOPP), total lipid hydroperoxide and protein carbonyl compounds (PCC) were similar between the control subjects and the patient group before treatment. Pyrrolized protein and TOS were significantly lower and thiol levels and TAC were significantly higher in the control subjects than in patients with hypogonadism. Treatment of hypogonadism resulted in a significant decrease in AOPP levels while a significant increase was determined in TAC. No significant change was found in MPO activity. In conclusion, patients with hypogonadism have an increased status of oxidative stress which is at least partially improved after appropriate therapy.