Objectives: This study aims to examine if the follow-up management service by National Health Insurance (NHI) for obesity persons leads to significant modification of the lifestyle and change of health status. Methods: Of persons who underwent health screening and were classified as obesity after periodic health screening by NHI in 2004, persons who took the follow-up management service were selected as case group and persons who took no service were selected as control group. The DW database of NHI was used to explore the effect of the follow-up management service on the modification of lifestyle and health status. Chi-square tests and t-tests, pairs t-tests were conducted with SAS 9.1 to examine the differences of health promotion effect between case vs. control group. Results: It was shows that of lifestyle behaviors, only exercise is significantly improved for case group compared with control group as the effect of the follow-up management service by NHI (2.11%p) (p=0.0435). Further, morbidity rate for control group was 2.05% higher than that of case group (p=0.0002). These results indicate that persons who received the follow-up management service better maintained their health significantly than persons who did not. Conclusion: The present study shows that the appropriate follow-up management services need to be provided for maximaizing potential effect of periodic health screening by NHI.