Benign prostatic hyperplasia (BPH) is one of the most common diseases of older men. But the pathogenesis of the relationship of erectile dysfunction and lower urinary tract symptoms (LUTS) in this patients while not fully understood. The article presents different pathophysiological theory, confirming this relationship. Drug therapy in patients with BPH and erectile dysfunction is mostly preferred option. Review of publications dedicated to using of phosphodiesterase type 5 inhibitors (PDE5 inhibitors) in patients with benign prostate hyperplasia (BPH) with assessment of PDE5 inhibitors efficiency on lower urinary tract symptoms and erectile function (EF). Existing pathophysiological theories of PDE5 inhibitors's mechanism of action on LUTS caused by BPH: theory of reduction of NO synthesis in pelvic organs endothelium, theory of metabolic syndrome and autonomous hyperactivity, theory of Rhokinase activity increase, theory of pelvic vessels atherosclerosis. Numerous researches on Sildenafil's, Tadalafil's and Vardenafil's effects on LUTS demonstrated significant improvements according to IIEF and IPSS/ QоL, however Qmax and Vres changes were insignificant and unreliable. Most of the publications contain data about treatment regimens. In review positive influence of PDE5 inhibitors mostly on irritative symptoms than Qmax, IPSS improvement were demonstrated. Pathogenetic mechanism connecting LUTS and EF is still unclear.