INTRODUCTION: Orthostatic hypotension (OH), a frequent feature of Parkinson's disease (PD) can contribute to falls and is usually related to the disease itself and/or to drugs. OBJECTIVES: To explore factors related to OH and to assess the concordance between abnormal blood pressure (BP) fall after standing and the presence of orthostatic symptoms. METHODS: Non-demented, non-operated idiopathic PD out-patients were questioned about the presence of orthostatic symptoms. Afterward, BP was measured 5-min after lying down and for 3-min after standing up. OH was defined as systolic and/or diastolic BP fall ≥ 20 and/or 10 mmHg after standing. Patients were further evaluated by the Unified PD Rating Scale (UPDRS) and their medications were recorded. RESULTS: 103 patients were included in this study (mean age = 66 ± 1 years, mean disease duration = 9 ± 1 years; mean UPDRS II+III in ON-state = 37 ± 2 points). Forty-one subjects (40%) reported the presence of orthostatic symptoms during the previous week and 38 (37%) had OH according to manometric definition. Independent factors related to OH, as assessed by logistic regression were age >68 years (OR, 95% CI=3.61, 1.31-9.95), polypharmacy (defined as intake of >5 medications, OR = 3.59, 1.33-9.69), amantadine (7.45, 1.91-29.07) or diuretics (5.48, 1.10-54.76), whereas the consumption of entacapone was protective (0.20, 0.05-0.76). The agreement between abnormal BP fall and presence of orthostatic symptoms was poor (kappa = 0.12 ± 0.1, p = 0.23). CONCLUSION: OH was significantly related to older age, polypharmacy and amantadine or diuretics intake, while entacapone exposure appeared to reduce the risk of OH. Low concordance between OH and orthostatic symptoms was observed.