Palpitations are a common problem in the ambulatory primary care setting, and cardiac causes are the most concerning etiology. Psychiatric illness, adverse effects of prescription and over-the-counter medications, and substance use should also be considered. Distinguishing cardiac from noncardiac causes is important because of the risk of sudden death in those with an underlying cardiac etiology. A thorough history and physical examination, followed by targeted diagnostic testing, can distinguish cardiac conditions from other causes of palpitations. Persons with a history of cardiovascular disease, palpitations at work, or palpitations that affect sleep have an increased risk of a cardiac cause. A history of cardiac symptoms, a family history concerning for cardiac dysrhythmias, or abnormal physical examination or electrocardiography findings should prompt a more in-depth evaluation for heart disease. Ischemic symptoms may signal coronary heart disease and associated ventricular premature contractions that may warrant exercise stress testing. Exertional symptoms accompanied by elevated jugular venous pressure, rales, or lower extremity edema should raise concern for heart failure; imaging may be required to assess for functional and structural heart disease.