OBJECTIVE:The aim of this study was to adapt the lifestyle questionnaire related to cancer in Turkish and investigate its validity and reliability. METHODS: This methodological study was conducted on 1,196 participants. Cronbach's α was used to assess validity and reliability. The internal consistency was evaluated using item-total correlation. RESULTS: The normed chi-square in this study was 5.87. The root mean square error of approximation was calculated as 0.051. The comparative fit index and the Tucker-Lewis Index were 0.83 and 0.81, respectively. The split-half method was used to test the reliability of the scale (Part 1 Cronbach's α: 0.826, Part 2 Cronbach's α: 0.812, and Adjusted Cronbach's α: 0.881). CONCLUSION: The Turkish version of lifestyle questionnaire related to cancer (8 subscales, 41 items) is a reliable and valid measure to evaluate lifestyle behaviors related to cancer in adults.