Background: The improvement of quality of life after percutaneous coronary intervention (PCI) has not been defined in Korean patients. Methods: To identify the factors affecting the quality of life (QOL) of the patients underwent PCI, 491 patients (60.7짹10.2 years, 348 male, 143 female) who underwent PCI and follow-up coronary angiogram 6 months later were analyzed between April 2004 and July 2006. The patients' replies were recorded while reading the structured questionnaire directly. A research tool was the Seattle Angina Questionnaire revised for Korean patients received the PCI. The questionnaire was composed all of 22 questions: six questions (age, sex, drinking, smoking, religion, and hobby activities) about general characteristics, six items (statin medication, restenosis, and lipid profiles about characteristics related with disease, and 10 items about QOL. Results: Mean age was 60.7짹10.2 years, and the percentage of those less than 55 years old was 26.7%. Male patients occupied as 70.9% of the whole, and the QOL score of a group under 55 years was higher than that of over 70 years. The QOL scores for groups of male, drinking, hobby activities, statin-administrated group and restenosis group were high. According to multivariate analysis, young age, male sex and low level of triglyceride were independent predictors of high QOL score. Conclusion: The younger age, male and low triglyceride were associated with better QOL after PCI.