OBJECTIVE: To investigate the relationship of hospital admissions due to unexplained syncope and orthostatic hypotension (OH) with subsequent cardiovascular events and mortality. METHODS: We analysed a population-based prospective cohort of 30 528 middle-aged individuals (age 58±8 years; males, 40%). Adjusted Cox regression models were applied to assess the impact of unexplained syncope/OH hospitalisations on cardiovascular events and mortality, excluding subjects with prevalent cardiovascular disease. RESULTS: After a median follow-up of 15±4 years, 524 (1.7%) and 504 (1.7%) participants were hospitalised for syncope or OH, respectively, yielding 1.2 hospital admissions per 1000 person-years for each diagnosis. Syncope hospitalisations increased with age (HR, per 1 year: 1.07, 95% CI 1.05 to 1.09), higher systolic blood pressure (HR, per 10 mm Hg: 1.06, 95% CI 1.01 to 1.12), antihypertensive treatment (HR: 1.26, 95% CI 1.00 to 1.59), use of diuretics (HR: 1.77, 95% CI 1.31 to 2.38) and prevalent cardiovascular disease (HR: 1.59, 95% CI 1.14 to 2.23), whereas OH hospitalisations increased with age (HR: 1.11, 95% CI 1.08 to 1.12) and prevalent diabetes (HR: 1.82, 95% CI 1.23 to 2.70). After exclusion of 1399 patients with prevalent cardiovascular disease, a total of 473/464 patients were hospitalised for unexplained syncope/OH before any cardiovascular event. Hospitalisation for unexplained syncope predicted coronary events (HR: 1.85, 95% CI 1.49 to 2.30), heart failure (HR: 2.24, 95% CI 1.65 to 3.04), atrial fibrillation (HR: 1.84, 95% CI 1.50 to 2.26), aortic valve stenosis (HR: 2.06, 95% CI 1.28 to 3.32), all-cause mortality (HR: 1.22, 95% CI 1.09 to 1.37) and cardiovascular death (HR: 1.72, 95% CI 1.23 to 2.42). OH-hospitalisation predicted stroke (HR: 1.66, 95% CI 1.24 to 2.23), heart failure (HR: 1.78, 95% CI 1.21 to 2.62), atrial fibrillation (HR: 1.89, 95% CI 1.48 to 2.41) and all-cause mortality (HR: 1.14, 95% CI 1.01 to 1.30). CONCLUSIONS: Patients discharged with the diagnosis of unexplained syncope or OH show higher incidence of cardiovascular disease and mortality with only partial overlap between these two conditions.