Venous thromboembolism (VTE) is a well-recognized postoperative complication of major surgery; the frequency in patients undergoing coronary artery bypass graft surgery (CABG), however, has not been well established. Early recognition of the signs and symptoms of VTE after CABG may be delayed because of expected postoperative findings such as donor vein graft extremity edema, left hemidiaphragm paralysis, left pleural effusion, and left lower lobe atelectasis. Five of 120 patients (4.1%) who underwent CABG at one institution from July 1 to October 31, 1988 developed pulmonary embolism (PE). The diagnosis of PE was delayed in these 5 patients, 2 of whom (40%) died as a result of embolic disease. These patients demonstrate the difficulty in promptly diagnosing PE in the postoperative CABG period and illustrate the substantial clinical impact of PE in patients who have undergone CABG.