. Prostate cancer - is a Malignant neoplasm arising from prostatic epithelium.  It is well known, that prostate cancer is the most common cancer in men population. Most patients, who underwent a biopsy of prostate, have expressed varying degrees of benign prostatic hyperplasia and, accordingly, symptoms, specific to the disease, including symptoms of the lower urinary (LUTS). , Uroflowmetry is a method widely used around the world to assess the degree of severity of infravesical obstruction .The aim was to determine the degree of influence of transrectal multifocal biopsy of the prostate under ultrasound control on the degree of infravesical obstruction .The study included patients with elevated serum PSA over 4 ng/ml with the volume (Vpr) of prostate from 20 cm³ to 90 cm³, volume of residual urine no more than 50 cm ³. Uroflowmetry was performed with the determination of the volume of residual urine at the primary treatment. At 21 day after transrectal multifocal prostate biopsy under Ultrasound control all patients underwent uroflowmetry. The age of patients ranged from 40 to 70 years. Patients were divided into 3 groups depending on the volume of the prostate gland. The first group consisted of 28 people where prostate volume ranged from 20 cm³ to 40 cm³, in the second group, consisted of 25 persons, prostate volume ranged from 41 cm³ to 60 cm³, and in the third group, consisted of 30 people, prostate volume ranged from 61 cm³ to 90 cm³. The following indicators of urofloumetry were determined as the following: voided volume, max flow rate, average flow, voiding time, flow time, time to max flow, and the volume of residual urine.This study has demonstrated a high risk of complications in patients with prostate volume of more than 60 cm3 caused by infravesical obstruction after prostate biopsy.