Objective: Chest pain is a major reason for emergency room care worldwide. The relationship between the Modified Heart Score and the presence of major cardiac events at 30 days after emergency admission was evaluated. Methods: Retrospective, observational study in a single centre on patients older than 18 years, who were treated for chest pain. The Modified HEART Score was applied at admission and related to the presence of major cardiac events (myocardial infarction, death, hospital re-admission due to cardiac causes, and percutaneous or surgical coronary revascularisation) at 30 days of follow-up. Results: Of 158 patients analysed, 17 (10.8%) adverse events were found at follow-up. The modified HEART score could predict adverse events in 4%; 21.4%, and 100% of patients with scores 0-3; 4-6, and 7-10, respectively (P =.0001). A modified HEART score greater than or equal to 4 was associated with more adverse events (OR: 4.52; 95% CI 2.76-7.39) with a sensitivity of 70% and specificity of 84%. Conclusions: The application of the modified HEART score is useful for stratifying patients with chest pain into low, moderate, and high risk of cardiovascular complications, which should help the emergency units to improve their protocols for triage and diagnosis of acute coronary syndromes.