Purpose: The purpose of this study was to explore the prevalence of Clornorchiasis and related factors, targeting inhabitants living in a 5 Km area of the Yeongsan River and to identify knowledge related to Clornorchiasis and intended behavioral changes related to risk of infection. Method: The data were collected from December 16, 2008 to January 10, 2009. A total of 553 questionnaires were distributed, 28 were deleted as answers were not complete, resulting in 525 copies being used for data analysis, which was done using frequency, percentage, x2-test, and t-test with the SPSS 12.0 program. Results: Clornorchiasis was found in 25 persons of the 525 (4.8%). As for knowledge on Clornorchiasis, the Clornorchiasis group had a higher mean score of 10.08 (±4.96), of a possible 17, than the negative group score of 9.42 (±4.81), but, the difference was not statistically significant. The intended behavioral change related to risk of infection, according to presence of infection or not, was statistically significant. Conclusion: Effective management of Clornorchiasis demands management targeted at the inhabitants living in all of the risk areas without any distinction according to sex, areas, live food diet or not, nor liquor consumption or not.