Objectives: Despite guidelines, admission rates and expenditures for syncope remain high. This may be caused by an imprecise definition of cardiovascular disease considered at risk and an overestimation of the role of comorbidities and advanced age. In a cohort of patients with undetermined syncope, we prospectively compared the short-term prognosis of patients at intermediate risk (i.e., with stable heart diseases or comorbidities, of any age) versus those at high risk for cardiogenic syncope and identified factors associated with serious events. Secondarily, we analyzed the current management of intermediate-risk patients.Methods: In a cohort of patients with undetermined syncope, we analyzed personal data, the presence of stable heart diseases or comorbidities, destination, length of hospitalization, incidence of serious events at 30 days, and costs.Results: In a 6-month period, 347 patients (185 male and 162 female, age 72.8 years) with undetermined syncope were enrolled, 250 at intermediate risk and 97 at high risk. Intermediate-risk patients were younger, with less frequent comorbidities and with a drastically lower incidence of serious events (0.8% vs. 27.8%, p < 0.001). Risk factors for cardiogenic syncope were the unique variable associated with serious events. Intermediate-risk patients were mostly admitted (62.8%) in an ordinary ward or into an emergency department observation unit; in the case of ordinary admission we observed a mean prolonged hospitalization (8.8 days), elevated costs ($270,183), and a high rate of unexplained syncope (51%).Conclusions: According to the results of this study, the authors believe that intermediate-risk patients could be safely discharged, with potentially significant costs saving. In prognostic stratification, priority is to seek risk factors for cardiogenic syncope while advanced age, stable heart diseases, or comorbidities likely lead to inappropriate hospitalization. ACADEMIC EMERGENCY MEDICINE 2016;23:941-948