A higher risk of suicidal attempt after subthalamic nucleus deep brain stimulation (STN-DBS) for Parkinson's disease (PD) has been consistently reported. We retrospectively analyzed 3 PD patients with suicide attempts after STN-DBS. All patients had normal pre- and immediate postoperative psychopathological and cognitive evaluations, with STN-DBS yielding a good motor benefit. Levodopa medication was markedly reduced. Albeit there was a significant reduction in dopaminergic medication, there was also a considerable time lag to suicide attempt. Impulsive behavior could have played a higher role, going unnoticed in punctual psychopathological examinations. STN-DBS patients need a closer postoperative psychiatric and behavioral follow-up.