Coronary heart disease (CHD) is the most common cause of death in the UK, accounting for around 125,000 deaths per year. Diet is a CHD risk factor that is modifiable, and therefore has the potential to alter the risk for CHD. At present, little is known about the dietary patterns of CHD patients. The present study aimed to assess the effectiveness of dietary advice administered to patients undergoing coronary artery bypass grafting (CABG) surgery. Dietary intake was assessed on three occasions (pre-operatively, 2 months after surgery and 1 year after surgery) by use of a food amount frequency questionnaire that had been previously validated. Patients were also asked to provide information on any dietary advice they had received. Complete data were available for 15 males, aged 51-79 years, who were admitted for CABG surgery. The absolute mean intakes of total fat, saturated fat and dietary cholesterol significantly increased 1 year after CABG surgery by 21%, 36% and 51%, respectively, and the choice of food items reflected this change in nutrient intake. These undesirable changes occurred despite the provision of dietary advice. This may consequently increase the risk of recurrent problems, and serve to promote further atherosclerosis in the arteries of such patients. The observations highlight the need to better understand the barriers to nutritional advice and compliance seen in CABG patients.