Unlabelled: INTRODUCTION AND OBJECTIVES. To study the significance of chest pain in the clinical practice of a Spanish hospital and to evaluate the impact of routine troponin determination., Methods: In our institution, routine serial measurements of troponins I and T were made in the evaluation of chest pain in 2000. We compared the results obtained in 1999 for all patients who visited the emergency room for chest pain and the patients who were hospitalized. We recorded the diagnosis at discharge, duration of the hospital stay, and associated costs., Results: In 2000, 1,820 patients with chest pain visited the emergency department, which was equivalent to 1.9% of visits and 7.5 cases per 1,000 people and year: 43% of these patients were hospitalized for suspected acute coronary syndrome as compared to 49% in 1999 (-12%; p > 0.001). Among the patients admitted, 28% were discharged with a diagnosis of non-ischemic chest pain. Troponin determinations were associated with a lower probability of admission due to unstable angina (11.5 vs 16.0%; -28%; p < 0.001) and non-ischemic chest pain (12.1 vs 14.5%; -16%; p < 0.05), and an increase in diagnoses of non-Q wave acute myocardial infarction (3.4% vs 1.8%; +89%; p < 0.01). Non-ST elevation acute coronary syndrome ACS required 3,751 days of hospitalization and 1,003,420 euros of cost, and troponin determinations were associated with a reduction in hospital stays of 832 days (-18.2%) and 185,100 euros (-15.6%)., Conclusion: Chest pain had a high incidence, 7.5, and generates high costs in hospital admissions. The routine use of serial troponin determinations was associated with a reduction in hospital admissions due to unstable angina and non-ischemic chest pain, and costs.