Chest pain is one of the frequent complaints in patients presenting to emergency rooms and ambulatory care clinics. For the primary care physician evaluating these patients, there are three essential steps in the evaluation of chest pain. The first step is to determine whether the chest pain is cardiac in origin or not. If the pain is suspected to be cardiac, then the next step would be to determine if the chest pain is secondary to an acute coronary syndrome (acute myocardial infarction or unstable angina) that requires immediate referral to an emergency room to initiate therapy and admit to the hospital. If the pain is not considered to be due to an acute coronary syndrome, then we proceed with a systematic approach to try to determine the likelihood that a particular patient has significant coronary artery disease (CAD). This is determined based on the patient's history, risk factors and electrocardiogram. Once the likelihood is assessed, this will determine what further invasive or non-invasive tests would be required to complete the patient's evaluation.