Psychosis is one of the most disabling non–motor symptoms of Parkinson's disease (PD). Common psychotic features in PD include visual hallucinations and delusions. However, not all PD patients will develop psychosis, and a variety of factors, both intrinsic and extrinsic, contribute to its occurrence. Dopaminergic dysfunction plays an important role, along with the role of other neurotransmitters, such as acetylcholine and serotonin. Apart from dopaminergic and other medications, other reported risk factors include increased age, comorbidities, cognitive impairment, sleep disturbances, visual processing deficits, genetic predisposition and Lewy body distribution. While the specific course of PD psychosis remains to be adequately described, it seems clear that psychotic symptoms, once present, are persistent and distressing. Optimal management includes identification of contributing potential causes, optimization of the environment, antiparkinsonian medication adjustment, and symptomatic management with specific medications such as quetiapine and clozapine and, in those with cognitive impairment, cholinesterase inhibitors.