Background: The patient reported outcome questionnaire Abdominal Hernia-Q is probably the most thoroughly validated patient-reported outcome measure specifically developed for patients undergoing ventral hernia repair. The present study aims to adapt and validate the Danish translation of the Abdominal Hernia-Q for patients undergoing groin hernia repair: the Groin Hernia-Q. Methods: This validation study will involve a total of 250 participants and it is divided into two substudies. Substudy 1 will focus on adapting the Abdominal Hernia-Q into the Groin Hernia-Q and assessing its content validity using the QQ-10 questionnaire. Substudy 2 will evaluate the structural validity, internal consistency, test-retest reliability, measurement error and construct validity of the Groin Hernia-Q, while also utilizing and comparing the results to the Carolinas Comfort Scale and Short-Form 12. Participants will be recruited both in a clinical setting and electronically. Data collection will be conducted through the platform Research Electronic Data Capture (REDCap). In addition to questionnaire data, this study will also involve perioperative and patient-related data extracted from the Danish National Patient Registry and the Danish Hernia Database. This study is part of the AFTERHERNIA Project. Conclusion: This study will provide a comprehensive validation of the Groin Hernia-Q, ensuring it becomes a valuable tool for assessing patient-reported outcomes in patients undergoing groin hernia repair. The questionnaire will contribute significantly to improved patient care through the AFTERHERNIA Project.