Neuropsychiatric symptoms (NPSs) are known to be frequent in Parkinson's disease (PD) with great impacts on the quality of life, but reports about the prevalence in institutions are few. Our aim was to investigate the prevalence of and risk factors for NPSs in institutionalized patients with PD in Taiwan. The National Health Research Institute executed a cross-sectional, community-based, observational study on residential long-term care service institutions. The diagnosis of PD was determined by physicians with the estimated Hoehn and Yahr stage of PD according to the EQ-5D-5L questionnaire. A total of 370 patients with PD (80.1 +/- 9.94 years old, 55.1% females) were included, and 139 (37.6%) had more than one NPS in the prior 3 months. The top three NPSs were nighttime behavior (65 (17.6%)), depression (53 (14.3%)), and fear/anxiety (49 (13.2%)). There were no differences between those with NPS and those without NPS in terms of age, gender, education, Mini-Mental State Examination, or Hoehn and Yahr stage. However, multivariate logistic regression analysis showed that genitourinary disease (odds ratio (OR) = 3.13; 95% confidence interval (95%CI) = 1.77-5.51) and psychiatric disorders (OR = 5.18; 95%CI = 3.09-8.69) may be associated with increased risk of NPSs. Increased physical restraint was observed in residents with advanced PD. Genitourinary disease and psychiatric disorders appear to increase the risk of NPSs in institutionalized residents with PD.