Background: The growing population of cancer survivors faces persistent physical and emotional challenges that significantly impact health-related quality of life (HRQL). To address these multifaceted needs, robust and culturally adapted patient-reported outcome measures, such as the Measure Yourself Concerns and Wellbeing (MYCaW®) questionnaire, are essential for understanding and improving survivors’ subjective experiences. Objective: This protocol outlines the systematic translation and cultural adaptation of the MYCaW® questionnaire into German. The MYCaW® questionnaire, a patient-reported outcome measure, is designed to capture individualized concerns and assess overall well-being, particularly in cancer care settings. By adhering to common guidelines, this research will provide a tool for assessing individualized concerns and patient needs among German-speaking cancer patients. Methods: Following International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines, this study will employ a structured methodology involving forward and backward translation, expert review, patient review process, and preliminary validation to ensure linguistic and cultural equivalence. The present study is approved by the ethics committee of the Medical Association Berlin with the reference number Eth-27/10. Construct validity will be assessed through comparison with the EORTC QLQ-C30 and the MIDOS questionnaire, to evaluate both quality of life and symptom burden. Results: Funding of the study was obatained in January 2023. Patient recruitment started in Q1 2023, and the cognitive debriefing phase is ongoing. Validation with the larger patient sample (n=120) is scheduled to conclude in Q4 2025, with publication of the study results anticipated in Q1 2026. The adaptation process will include translation, expert review, and cognitive debriefing with patients and healthcare professionals to ensure linguistic clarity and cultural relevance. Conclusions: The translation and adaptation of MYCaW® into German will contribute to expanding the availability of validated patient-reported outcome measures for German-speaking populations. By following rigorous international guidelines, this study aims to produce a reliable, culturally appropriate, and linguistically adapted German version of the MYCaW® questionnaire for assessing patient concerns and well-being in oncology and supportive care settings. Future validation studies will be necessary to assess the psychometric properties of the adapted questionnaire and its applicability in clinical and research contexts. Potential challenges, such as maintaining conceptual equivalence in translation and ensuring broad representativeness in the validation process, will be addressed through iterative refinement. Once validated, the German MYCaW® will provide a valuable resource for patient-centered research and care, helping to capture individualized concerns that might be overlooked by standardized instruments. Clinical Trial: German Clinical Trials Register; DRKS00013335; https://drks.de/search/de/trial/DRKS00013335.