Many clinical studies have shown, that α1А selective alpha blockers are more tolerable to patients with benign prostatic hyperplasia (BPH), than non-selective ones. is is especially important consideration in patients with the risk of adverse cardio-vascular effects. One of the new α1А selective alpha blockers is silodosin. ere is enough evidence, related to the efficacy and safety of silodosin in patients with lower urinary tract symptoms (LUTS) due to BPH. Aim of the observation: evaluation of the efficacy of silodosin in patients with severe LUTS due to BPH. We have included 30 patients with age of 47-75 years with LUTS due to BPH, which received silodosin 8 mg once a day. Оbservation included 3 visits: V0 – screening, V1 – 5 days aer initiation of treatment, V2 – 60 days aer treatment initiation. During every visit patients fulfilled the questionnaire IPSS/QoL, underwent uroflowmetry with the estimation of postvoid residual volume (PVR). Efficacy criteria were: changes in IPSS/QoL, Qmax and PVR dynamics. e results showed that silodosin have significantly improved main clinical and urodynamic parameters (IPSS, QoL, Qmax, Qave, Vcomp, Vres), showing rapid onset of the effect. Prominent improvement was observed with regard to IPSS (53.3%) and Qmax (73.3%). It was shown that patients with moderate LUTS demonstrated better improvement while being on silodosin. Patients with IPSS < 18 and Qmax > 10 ml/sec could demonstrate a good response to silodosin.