Although therapeutic lifestyle modification (TLM) has been recommended as a cornerstone treatment of metabolic syndrome (MetS), little is known about the biobehavioral effects of a TLM program for patients in a community. The purpose of this study was to examine the effects of a 6-month TLM program on MetS risk factors and health-related qualities of life (HRQOL) among middle-aged and older women in a community in Korea. Fifty-two women (mean age, 62.7 +/- 9.0 years) with MetS were recruited from 3 community health centers and were randomly assigned to the intervention (n = 31) or control (n = 21) groups. The patients in the intervention group participated in supervised TLM sessions for 6 months. The TLM program included health monitoring, counseling, health education, exercise, and dieting. Metabolic risk factors and HRQOL were measured at baseline, during the study (month 3), at completion (month 6), and post completion (month 12) of the TLM program. Compared with the control group, the TLM group showed significantly greater reductions in body weight (P < .001) and waist circumference (P < .001); these effects were sustained for 6 months after intervention. With regard to HRQOL, the TLM group showed greater improvements in physical function (P = .017), general health (P < .001), vitality (P = .008), and mental health (P = .027). These improvements, however, were not sustained after the intervention. The results indicate that a nurse-led systematic TLM program may be an effective strategy for managing middle-aged and older women with MetS at a community level.