OBJECTIVE: The aim of the present study was to evaluate the change in health related quality of life (HRQoL) among elective coronary artery bypass grafting (CABG) patients. METHODS: A total of 302 CABG patients were included in the study. Complete pre-, peri- and postoperative data were collected comprehensively in a database. HRQoL was measured by the 15D instrument. The 15D is a non-disease-specific, 15-dimensional, standardized and self-administered measure of HRQoL that can be used both as a profile and single index score measure. Baseline assessment was carried out before coronary angiography and assessment was repeated 6 and 18 months after surgery. Data were analysed by gender and in three age groups, i.e. patients <65 years, 65-74 years and > or = 75 years. RESULTS: Thirty day mortality was 1.0%, and the survival rate at 6 and 18 months was 99.0% and 96.7%, respectively. Preoperative HRQoL of CABG patients was lower in comparison to age- and gender-standardized Finnish population (P<0.001). HRQoL of the patients improved significantly after CABG and the positive change lasted over the whole observation period, despite a slight decrease of 15D scores until 18 months. Although male patients had a higher preoperative HRQoL than women (P=0.005), both genders benefited similarly from the operation. In the patients > or = 75 years, the initial improvement of HRQoL returned to the preoperative level 18 months after the surgery. CONCLUSIONS: CABG patients experience a significant improvement in their HRQoL within 6 months after the operation and the effect remains through a mid-term observation time. However, expectations of improved HRQoL may have a limited value in decision making for surgery of coronary artery disease (CAD) for patients more than 75 years old.