Purpose: This study was done to investigate the knowledge, attitude and prevalence status of Clonorchiasis Sinensis (C.S.) for inhabitants in the Nakdong riverside area. Method: Data were collected from December 16, 2008 to January 10, 2009. Participants were 552 people who responded to a questionnaire and had a stool examination. Results: The overall prevalence of C.S. was 13.8%. As for knowledge of C.S., the Clonorchiasis group had a mean score of 10.78 (±3.54) on a 17-point scale compared to a score of 10.58 (±4.15) for the negative group. The intended behavioral change related to risk of infection, according to presence of infection or not, was not significant but the Clonorchiasis group had a greater desire for behavioral change intention than the negative group. Conclusion: These results suggest that prevalence investigation of C.S. in all areas in the Nakdong riverside is needed and indicates that it is necessary to set up persistent and systematic management programs for patient care and prevention of C.S..