Objective. To assess the clinical efficacy of deep brain stimulation (DBS STN) of the subthalamic nucleus in patients with Parkinson´s disease (PD) compared to pharmacological treatment. Material and methods. DBS STN was applied to 22 patients (mean age 53.2 years, mean disease duration 9,6 years). The control group included 28 patients (mean age 54.2 years, mean disease duration 9,6 years) with PD who received pharmacological treatment. Patients were examined in OFF-medication and ON-medication conditions at 3, 6, 9, 12, 24, 36 months. The Unified Parkinson's Disease Rating Scale (UPDRS) part II, III, IV, the Hoehn and Yahr scale, the Schwab and England Scale, PDQ-39, the Hamilton Rating Scale for depression and the Spielberger Anxiety Scale were administered. All patients had motor fluctuations and dyskinesias. Results and conclusion. We demonstrated that DBS STN improved UPDRS II, III scores, reduced dyskinesias and motor fluctuations. After surgery, dopaminergic therapy was reduced by approximately 54.5%. In the control group, levodopa dose was increased by 20.5% to 36th month.