OBJECTIVES:  Most antipsychotics are considered potentially inappropriate in patients with Parkinson’s disease (PD). Limited research exists regarding factors contributing to the use of antipsychotics in patients with PD. This study examined the incidence and predictors of antipsychotic use among patients with newly diagnosed PD. METHODS: This cohort study used a large administrative database from 2000 to 2015 the Medical Outcomes Research for Effectiveness and Economics Registry (MORE2 Registry^®). The study sample included adult patients with PD (ICD-9-CM 332.0). Patients were followed for 3 years and Cox regression was used to examine factors associated with initiation of antipsychotics after PD diagnosis. Several demographics and clinical characteristics were included in the Cox model based on previous literature and availability in data. RESULTS: The study population included 1,470 patients with Parkinson’s disease. The mean age of the sample was 72.06 years (SD = 9.86). The incidence of antipsychotics use was 19.25% over 3-years follow up and quetiapine was the most frequently used antipsychotic agent (44.88%) in this study. The likelihood of using antipsychotics was significantly higher for PD patients with a history of antipsychotics use (Hazard Ratio, HR=2.08, P<0.01), dementia (HR=2.02, P<0.01), depression (HR=1.91, P<0.01), and schizophrenia (HR=1.49, P=0.02). Antipsychotics were less likely to be prescribed for PD patients using levodopa (HR=0.59, P<0.01), dopamine agonists (HR=0.69, P=0.02), catechol-O-methyl transferase inhibitors (HR=0.61, P=0.04) or other antiparkinson agents (HR=0.733, P=0.04). CONCLUSIONS: Antipsychotics are commonly used to control behavioral symptoms of patients with PD; however, most of these are considered potentially inappropriate in PD. Understanding the factors contributing to the use of antipsychotics can be helpful in optimizing use of these medications and improving pharmaceutical care for patients with PD.