연구의 필요성국내에서의Purpose: This study was to develop and evaluate the clinical utility of a nursing educational program to reduce the cancer worry of colorectal cancer patients' family members (RCW-FM) in Korea. Methods: The RCW-FM was developed based on several preliminary studies: an ethnographic and two quantitative studies to understand the educational needs among Korean colorectal cancer patients and their families. A one week clinical genetic educational course for clinical cancer nurses was implemented, and the RCW-FM led by cancer genetic nurses was constructed. A one group pretest-posttest design was implicated to evaluate the change of the family members' knowledge about colorectal cancer (KCR) and the level of the reduction of cancer worry (CWR). Results: The mean score for KCR significantly increased from 11.75 ± 1.28 to 13.87 ± 1.13 (p< .05). The mean score of CWR was 4.25 ± .89. Conclusion: This new RCW-FM is a satisfactory educational program for reducing the cancer worry of the colorectal patients' family members. But it needs to provide more practical, specific information including a long term perspective, tailored specifically for what Korean families want to know. It should also incorporate the preventive guidelines recommended for high risk hereditary or familial colorectal cancer. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.