The purpose of this study was to examine colonoscopy adherence and attitudes toward colorectal cancer (CRC) screening in individuals who underwent Lynch syndrome genetic counseling and testing. We evaluated changes in colonoscopy adherence and CRC screening attitudes in 78 cancer-unaffected relatives of Lynch syndrome mutation carriers before pre-test genetic counseling (baseline) and at 6 and 12 months post-disclosure of test results (52 mutation negative and 26 mutation positive). While both groups were similar at baseline, at 12 months post-disclosure, a greater number of mutation-positive individuals had had a colonoscopy compared with mutation-negative individuals. From baseline to 12 months post-disclosure, the mutation-positive group demonstrated an increase in mean scores on measures of colonoscopy commitment, self-efficacy, and perceived benefits of CRC screening, and a decrease in mean scores for perceived barriers to CRC screening. Mean scores on colonoscopy commitment decreased from baseline to 6 months in the mutation-negative group. To conclude, adherence to risk-appropriate guidelines for CRC surveillance improved after genetic counseling and testing for Lynch syndrome. Mutation-positive individuals reported increasingly positive attitudes toward CRC screening after receiving genetic test results, potentially reinforcing longer term colonoscopy adherence.