In this article we investigate the changes observed in the scales that quantify the quality of life (PDQ-39) in patients that have already completed 1 and 2 years of bilateral subthalamic stimulation (DBS-STN). Fourteen patients were evaluated 1 year after DBS-STN; the evaluation was repeated on 11 of them, 2 years after surgery. All of them suffered from Parkinson's disease with a 14.3 (±5.7) years history of motor complications. Patients were selected according to CAPSIT criteria. All of them were implanted bilateral electrodes in the subthalamic nucleus. The parameters applied were UPDRS II, UPDRS III, PDQ-39, and the scale of quality of life for caregivers (SQLC). Scorings in motor scales (UPDRS III) improved 45% in relation to the first year, and 48% in relation to the second year (P < 0.001). Patient's quality of life (PDQ-39 summary index) improvement was 62% 2 years after surgery (P < 0.001), and caregivers' quality of life improvement was 68% (P = 0.002) by the same time. DBS-STN is a therapy that efficiently improves the quality of life of selected patients with Parkinson's disease. This improvement is still present 2 years after surgery and has a positive impact on caregivers quality of life.