Current evidence suggests that 30–50% of cancers are attributable to established lifestyle risk factors. Cancer-screening has been identified as an opportunity for delivering advice on lifestyle behaviour change for cancer prevention. This study aimed to evaluate the feasibility and acceptance of promoting advice on the latest evidence-based lifestyle recommendations for cancer prevention at the time of colorectal cancer screening at two hospitals in Lyon, France. This feasibility study included 49 patients (20 men and 29 women) who were invited for colonoscopy. Patients received a leaflet with lifestyle recommendations for cancer prevention, accompanied with a logbook to plan and monitor their behavioural changes. Feedback from patients, hospital staff, and researchers was received via evaluation questionnaires (n = 26) completed after testing the educational material for at least two weeks and via two focus group discussions (n = 7 and n = 9 respectively) organized at the end of the study. All interviewed patients were interested in lowering their cancer risk, and the majority felt ready to change their lifestyle (88%), although most did not know how to decrease their risk of cancer (61%). All patients found the educational material easy to understand and sufficiently attractive and 50% of the patients reported having achieved at least one of the healthy behaviours recommended within the two weeks following the intervention. All hospital staff and almost all patients (92%) involved found that the screening program and the visits planned for colonoscopy was an appropriate moment to provide them with the educational material. This feasibility study has shown that the content, paper-based format, and time of delivery of the intervention were adequate. Health professionals seem to be willing to provide lifestyle recommendations, and patients appear interested in receiving advice for lowering their cancer risk during screening visits.