OBJECTIVE To investigate the usefulness of stress testing before discharge in patients assessed low to intermediate risk of acute coronary syndrome (ACS). METHODS A prospective observational study was undertaken of patients presenting to the ED with suspected myocardial ischaemia. After negative initial electrocardiogram (ECG) and serum troponin testing, patients were admitted to the emergency short stay unit (ESSU) for further evaluation using a chest pain protocol that included stress testing as the final risk stratification tool. The primary outcome measure was evidence of myocardial ischaemia at stress testing. RESULTS Of the 300 patients enrolled and followed up, there were no deaths at 30 days and no myocardial infarcts in patients discharged from the short stay. Two patients (0.67%) had positive serum troponin levels at 6 h after the onset of chest pain and were diagnosed with non-ST segment elevation myocardial infarctions. Three patients (1%) had abnormal stress testing and were admitted to hospital from ESSU. On review, all three patients were high risk, according to The National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand guidelines. CONCLUSION The present study showed that an ED short stay unit can effectively evaluate and manage patients with low and intermediate risk of ACS. The study suggests that patients with low and intermediate risk for ACS might safely be discharged after normal serial ECG and cardiac biomarkers, with a view to early outpatient stress testing. With strict adherence to admission criteria, there does not appear to be any benefit of stress testing before discharge.