AIM: To describe changes in chest pain and dyspnoea during a period of 15 years after coronary artery bypass grafting (CABG) and to define factors at the time of operation that were associated with the occurrence of these symptoms after 15 years. DESIGN: Prospective observational study in western Sweden. SUBJECTS: All patients who underwent first-time CABG, without simultaneous valve surgery, between 1 June 1988 and 1 June 1991. There were no exclusion criteria. FOLLOW-UP: All patients were followed up prospectively for 15 years. The evaluation of symptoms took place through postal questionnaires prior to and 5, 10 and 15 years after the operation. RESULTS: Totally, 2000 patients were included in the survey and 904 (45%) of them survived to 15 years. Among these 904 survivors, the percentage of patients with chest pain increased from 44% to 50% between the 5- and 15-year follow-up (p=0.004). The percentage of patients who reported symptoms of dyspnoea increased from 60% after 5 years to 74% after 15 years (p<0.001). Factors at the time of surgery that independently tended to predict chest pain after 15 years were higher age (p=0.04) and prolonged duration of symptoms prior to surgery (p=0.04). Predictors of dyspnoea after 15 years were higher age (p<0.0001), the use of inotropic drugs at the time of surgery (p=0.001), a history of diabetes (p=0.01) and obesity (p=0.01). CONCLUSION: After CABG, relief from chest pain and dyspnoea is generally maintained over a long period of time. Eventually, however, functional-limiting symptoms tend to recur and about half the patients report symptoms of chest pain, while three-quarters report dyspnoea after 15 years. Even if no clear predictor of chest pain was found at the time of surgery, age, the use of inotropic drugs, diabetes and obesity predicted dyspnoea.