Introduction: We report our operative observations with STN stimulation for Parkinson's disease in 45 patients. Methods: Ten patients had previous surgery for Parkinson's disease. Radiological localization was done with MRI. One trajectory microelectrode recording was obtained in most, and macrostimulation in all. A period of trial stimulation followed, Kinetra and Itrel II generators were used. All patients received prophylactic antibiotics. A postoperative MRI was obtained. One patient was not definitively implanted. Results: Targeting was accomplished by stereotactic coordinates or a semidirect visual recognition. Time for bilateral electrodes placement was 3 h 45 min and for generator placement 1 h 15 min. For 5 electrodes, a second trajectory was necessary for final placement. The interval between the operations was 5 days. There were 7 instances of transient confusional state, one case of air embolus, one seizure at coagulation of the dura. There were no surgical mortality, hemorrage, infection or permanent neurological deficits. Four electrodes required repositioning after trial stimulation period. One connector wound dehiscence required revision. Microelectrode recording demonstrated the expected findings in over half the trajectories. 60% of the patients followed at our institution and for 3 months or more postoperatively have remained medication-free; the others have reduced their treatment by 60%. Conclusion: STN stimulation for PD provides the same results as optimal medication treatment in many patients. MRI proves to be reliable in targeting the STN. The reduced number of trajectories for microrecording and the short operating time, however associated with satisfactory results, may contribute to the low morbidity.