Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment for advanced Parkinson's disease with levodopa-induced motor complications. Randomized controlled studies have shown that motor fluctuations and quality of life are significantly more improved by STN-DBS than by best medical treatment. The main delay before neurosurgery is currently 14 years after diagnosis. Clinical pilot data suggest that neurosurgery performed already with beginning motor fluctuations and an average disease duration of 7 years may lead to earlier improvement of motor deficits and quality of life, thus preventing disease-related psycho-social decline, and extending the period of beneficial effects of STN-DBS. Results of an ongoing multicenter trial (EARLYSTIM) comparing the effects of STN-DBS and best medical treatment on motor symptoms, quality of life, and psycho-social adaptation will be available in 2 years time and will clarify whether or not early STN-DBS is superior to best medical treatment.