Purpose: The study was conducted to clarify effects of a clonorchiasis prevention education program for clonorchiasis prevention lecturers. Methods: The research adopted a single group pretest-posttest design to see effects of the educational program to prevent Clonorchis sinensis infection. The subjects of this study were 74 clonorchiasis prevention lecturers from primary health care facilities. The pretest was conducted before the clonorchiasis prevention education program and the post test was done after the 2-day program in August, 2011. Descriptive statistics, t-test, and ANOVA were conducted to analyze the data. Results: The confidence level in Clonorchiasis management activities was improved significantly from 4.1±0.53 points before the education to 4.4±0.46 points after the education (t=-5.117, p<.001). The knowledge level about prevention of Clonorchis sinensis was improved significantly from 16.1±2.72 points before the education to 18.3±1.14 points after the education (t=-6.629, p<.001). Conclusion: The results suggest that the education program was effective in improving the confidence and knowledge levels in Clonorchiasis management activities for the clonorchiasis prevention lecturers. Based on the results of this study, continuous research on how the increased knowledge and confidence levels of Clonorchis sinensis prevention affect the prevalence of Clonorchis sinensis infection.