BACKGROUND: Weight loss in obese patients has been shown to decrease plasma lipid level and high blood pressure, to improved glycemic control in diabetic patients and to decrease cardiovascular risk in obese patients. But, study for association of weight loss and Health related Quality of Life is not well known yet worldwide. This study was to determine whether weight loss would associate with improvements on Health Related Quality of Life. METHODS: Participants was recruited in 48 obese patient visiting obesity clinic of Family Medicine of Sungkyunkwan University Hospital. 27 patients who answered mailed questionnaire was analyzed. Health Related quality of life was measured by Catholic Medical Center Health Survey(CMCHS) V 1.0. Questionnaire included not only Health Related Quality of Life but also alcohol habit, excercise, smoking, marital status, economic status, education. RESULTS: In multiple regression analysis, weight loss is statistically significant differences on satisfaction, vitality, physical function, social function, role limitation general health dimensions of CMCHS. CONCLUSION: The Results of this study demonstrate that weight loss on obese patients may be associated with an improvement in Health Related Quality of Life.