Introduction: An initial version of the Reengagement Life Goal Assessment Tool for Cancer Survivors (ReGAT-C) was designed to measure the quality of life goal-setting practice conducted by responsible healthcare professionals along with nonterminal cancer survivors undergoing inpatient cancer treatment. This study aimed to test content validity of the ReGAT-C and revise it.Methods: Eleven experts and nine healthcare professionals participated in this study. Content validity assessments using questionnaires and focus group interviews were conducted with experts. Cognitive interviews were conducted with healthcare professionals. The content validity index was calculated based on expert questionnaires, and these interview data were analyzed by inductive and deductive approaches. When the ReGAT-C was substantially revised, it was retested through questionnaires.Results: The initial version of the ReGAT-C was substantially revised and three new items were added, resulting in the development of a revised version of the ReGAT-C with 21 items. All participants reevaluated the ReGAT-C, and the revised version was verified to have content validity.Conclusions: The revised ReGAT-C would contribute to enabling healthcare professionals to assess whether they are based on collaboration with cancer survivors and multidisciplinary teams by reflecting on their own life goal-setting practice.