Purpose: The purpose of this study was to estimate the effects of an infection control program on the Clonorchis sinensis (CS) infection ratio, CS-related knowledge and health behavior of people living near the Geum River. Method: A one-group pretest-posttest design was used with 102 participants. For 12 months the participants were provided with promotion announcements, health education, counseling, and medication. Outcome variables measured were the CS infection ratio by stool examination, CS-related knowledge and health behavior from self-report questionnaires. The pre intervention data were collected from January to February 2008 and the post intervention data during the same period in 2009. Collected data were analyzed using descriptive statistics, generalized estimating equation analysis, and paired t-test with SPSS for Windows version 15.0. Results: In the pre test 21 of the 102 participants showed infection with CS for the first time. In the post test 9 were newly infected with CS, and one was re-infected. The CS-related knowledge was significantly improved after the infection control program (p<0.05). The CS-related health behaviors did not improve. Conclusion: These results showed that an infection control program is effective in decreasing CS infection ratio and improving CS-related knowledge of people living near the river.