Abstract Background Culturally sensitive, reliable and valid cultural belief scales for colorectal cancer (CRC) screening in Koreans in the Republic of Korea are not available in the literature. The purpose of this study was to adapt and validate existing cultural belief scales for CRC screening in Koreans. Methods Individual interviews, expert reviews, and a pilot test were conducted for instrument adaptation, and a cross-sectional survey with 884 Koreans was conducted for instrument validation. Construct validity using exploratory and confirmatory factor analyses and reliability of the Korean version of the instruments were examined. Results Exploratory factor analysis using c four factors that accounted for 48.12% of the variance. The validity and reliability of the cultural belief scales were supported by confirmatory factor analysis and Cronbachâ s alpha. Conclusions The results of the present study showed that the four-factor cultural belief scales were culturally sensitive, reliable and valid in Koreans. The final cultural belief scales could be used to identify cultural beliefs more accurately and specifically, as well as to develop effective interventions to increase CRC screening in Koreans in the Republic of Korea.