Different authors estimate the prevalence of hypogonadism and erectile dysfunction at 1.7% to 35%. The contribution of androgens playing an important role in regulation of erection remains the subject of extensive investigations. To date, experimental and clinical studies have demonstrated that androgen deficiency leads to degeneration and apoptosis of smooth muscle cells followed by fibrosis of cavernous bodies, impaired expression of endothelial and neuronal NO synthase, decreased arterial inflow and increased venous drainage of the cavernous bodies, enhanced sensitivity to mediators of vasoconstriction, impaired NO-mediated relaxation of smooth muscles in response to sexual stimulation, reduced expression of type 5 phosphodiesterase (PDE-5). Moreover, hypogonadism and erectile dysfunction are frequently associated with cardiovascular disorders, diabetes mellitus, metabolic syndrome, dyslipidemia, hypercholesterolemia, hypertriglyceridemia, and obesity. The main purpose of hormonal substitution therapy is to maximally normalize the physiological concentration of plasma testosterone and to eliminate clinical manifestations of androgen deficiency. The treatment with testosterone-containing preparations is indicated only for patients with clinical symptoms and laboratory findings suggestive of hypogonadism. The testosterone-based preparations for intramuscular administration currently find wide application for this purpose. Testosterone substitution therapy enhances libido, increases the frequency of morning erection, and improves sexual quality of life at large. It is worthy of note that treatment with these preparations is well tolerated by the patients. Control over hormonal substitution therapy with testosterone preparations implies evaluation of the clinical response and achievement of the target testosterone level in blood plasma. Also. it is necessary to measure PSA, perform digital rectal examination, and determine the hematocrit level prior to the initiation of the treatment, 3 and 6 months after its termination, and every 6 months thereafter. To conclude, androgens are natural stimulators maintaining sexual function in men. Patients with hypogonadism and erectile dysfunction should be managed by combined therapy with androgens and PDE-5 inhibitors.