Abstract Objective The study aimed to compare the efficacy of the Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk score, San Francisco Syncope Rule, and clinical judgment in assessing the short-term prognosis of syncope. Methods We studied 488 patients consecutively seen for syncope at the emergency department of 2 general hospitals between January and July 2004. Sensitivity, specificity, predictive values, and likelihood ratios for short-term (within 10 days) severe outcomes were computed for each decision rule and clinical judgment. Severe outcomes comprised death, major therapeutic procedures, and early readmission to hospital. Results Clinical judgment had a sensitivity of 77%, a specificity of 69%, and would have admitted less patients (34%, P < .05 vs decision rules). The OESIL risk score was characterized by a sensitivity of 88% and a specificity of 60% (admission 43%). San Francisco Syncope Rule sensitivity was 81% and specificity was 63% (admission 40%). According to both clinical rules, no discharged patient would have died. With combined OESIL risk score and clinical judgment, the probability of adverse events was 0.7% for patients with both low risk scores, whereas that for both high risk scores was roughly 16%. Conclusion Because of a relatively low sensitivity, both risk scores were partially lacking in recognizing patients with short-term high-risk syncope. However, the application of the decision rules would have identified all patients who subsequently died, and OESIL risk score and clinical judgment combined seem to improve the decision-making process concerning the identification of high-risk patients who deserve admission.