BACKGROUND: Judgment of quality of life after coronary artery bypass surgery is usually based on objective measures of cardiovascular status. Quality of life cannot be determined solely objectively because such indicators do not explain how persons perceive and experience their lives. OBJECTIVES: To assess the quality of life and mood state over time in patients undergoing coronary artery bypass grafting and to improve understanding of subjective perceptions of well-being and how these perceptions change over time. METHODS: Three questionnaires, the Quality of Life Index, the Medical Outcomes Study 36-Item Short-Form Health Survey, and the Profile of Mood States, were administered at 3 different times (before surgery, 6 weeks after surgery, and 3 months after surgery) to a convenience sample of hospitalized adults undergoing coronary artery bypass surgery for treatment of coronary artery disease. RESULTS: For all 3 questionnaires, responses differed significantly over time. Mean scores were significantly different over time for total mood disturbance (P = .03), the socioeconomic domain of the Quality of Life Index (P = .02), and the physical functioning (P = .004), vitality (P = .007), and social functioning (P = .002) dimensions of the 36-item short-form survey. CONCLUSIONS: Subjective perceptions of physical and psychological well-being changed significantly from before surgery to 3 months after surgery. Measures of mood state, physical functioning, vitality, and social functioning improved significantly over time. However, satisfaction with the socioeconomic domain decreased significantly from before surgery to 3 months after surgery.