OBJECTIVE: To describe the occurrence of prodromal symptoms in suspected acute myocardial infarction (AMI) and to relate such symptoms to final diagnosis and previous history. DESIGN: Prospective study. SETTING: Coronary care unit in Sahlgrenska Hospital in Göteborg, Sweden. PATIENTS: 914 patients admitted to the coronary care unit for suspected AMI. OUTCOME MEASURES: Chest pain within the last 48 hours or other prodromal symptoms. RESULTS: Among patients in whom AMI developed, 57% reported prodromal chest pain and 61% reported other prodromal symptoms. Size, location, or type (Q-wave versus non-Q-wave AMI) did not influence outcome. Women reported more prodromal symptoms than men (p < 0.05), whereas age did not influence results. A similar proportion of patients with no confirmed AMI reported prodromal symptoms. Fifty-nine percent of patients with prodromal symptoms had wished to contact a physician if possible, and in fact one third did so. Two thirds of all patients were at rest, and one third reported some emotional distress before onset of the symptoms that brought them to hospital. CONCLUSION: A large proportion of patients with suspected AMI experienced prodromal symptoms before onset of suspected AMI. Such symptoms were more common in women but were not affected by size, location, or type of AMI. The symptoms were so severe that 59% of the patients with such symptoms wished to contact a physician before arrival in hospital.