A descriptive follow-up study of a hospital based chest pain clinic set up for the identification of patients with unstable angina and acute myocardial infarction. The clinic is staffed by a cardiologist-in-training seeing patients on the day of referral by general practitioners because of acute chest pain of unclear origin. Over 6 months, 174 patients were assessed, 34 (19.5%) had a diagnosis of unstable angina or acute myocardial infarction (acute coronary syndrome), 52 (30%) had non-acute cardiac pain and 88 (50.5%) had non-cardiac pain. Of those with a clinical diagnosis of acute coronary syndrome, 5 were subsequently shown to have non-cardiac pain, 8 had acute myocardial infarction and 21 had unstable angina, One month follow-up information was available on 136 of 139 (98%) patients not admitted to hospital via the chest pain clinic. 3 were admitted to hospital within the following 4 weeks because of myocardial infarction in 1 and unstable angina in 2, One year follow-up was available on 118 patients, One patient was admitted with unstable angina 6 months later and one patient sustained sudden cardiac death 3 months later, In the absence of the clinic, general practitioners would have arranged hospital admission for 66 (48%) or assessment in the emergency department for 13 (9%) of those discharged. Almost all general practitioners found the service helpful, The chest pain clinic was well received and provided an efficient method of identifying patients,vith acute coronary syndrome and minimised unnecessary admissions.