Impulse control disorders in Parkinson's disease (PD) are mainly observed in connection with a medication with dopamine agonists. They are seen in up to 17 % of such treated patients and comprise pathological gambling, pathological buying, compulsive sexual behavior and binge eating disorder. Besides the medication with dopamine agonists, an individual vulnerability, possibly of genetic origin, seems a necessary prerequisite for these disorders to occur. Functional imaging studies have shown a diminished activation of the reward system in response to rewards. In addition, dramatic differences in the activity of frontolimbic control areas have been observed between PD patients with and without impulse-control disorders. An experimentally tractable consequence of increased impulsivity in PD is a steeper delay discounting function in intertemporal choice paradigms. This review concludes with a discussion of the practical consequences of the research findings on impulse-control disorders for the management of PD patients.