OBJECTIVE: To prospectively study the improvement in quality of life (QoL) after coronary artery bypass surgery (CABG). PATIENTS AND METHODS: Consecutive patients (n = 2121) who underwent CABG at Sahlgrenska University Hospital between 1988 and 1991 received 3 questionnaires for the study of QoL: the Physical Activity Score, the Nottingham Health Profile and the Psychological General Well-being Index, which were responded both before surgery and at 3 months (n = 1059), 1 year (n = 1045) and 2 years (n = 1027) postoperatively. RESULTS: All differences were tested against baseline. The Physical Activity Score improved (mean 4.3 before CABG, 3.1, 3 months after (P < 0.0001), and 2.8, 2 years postoperatively (P < 0.0001)). The Nottingham Health Profile score improved (mean 20.5 before CABG, 11.4, 3 months (P < 0.0001), and 10.4, 2 years postoperatively (P < 0.0001)). The Psychological General Well-being Index improved (mean 91.1 before CABG, 103.8, 3 months (P < 0.0001), and 105.8 (P < 0.0001), 2 years after CABG). The subscale analyses of the Nottingham Health Profile and the Psychological General Well-being Index 2 years after CABG showed the greatest improvement in areas reflecting physical capacity and pain, to be followed by mental qualities. At 2 years after CABG only sexual problems were still markedly frequent, and independent predictors for sexual problems after surgery were preoperative problems (P < 0.00001), male sex (P < 0.0001), and diabetes mellitus (P = 0.0008). CONCLUSION: QoL was markedly and significantly improved after CABG. The major improvement was seen already at 3 months, with further slight improvement observed 2 years after surgery. The major improvement was found in areas reflecting physical capacity and pain, which is consistent with symptomatic and objective measurements after CABG. In contrast to the overall improvement in QoL sexual problems were still markedly common 2 years after CABG. The mechanism for this is not fully understood and needs further investigation.