Patient-reported outcome measures are an important component of outcomes assessment in clinical trials to assess the treatment of femoroacetabular impingement (FAI). This review of disease-specific measures and instruments used to assess the generic quality of life and physical activity levels of patients with FAI found no conclusive evidence to support a single diseasespecific questionnaire. Using a systematic review of study methodology, the Copenhagen Hip and Groin Outcome Score and the 33-item International Hip Outcome Tool scored the best. Nevertheless, both of these instruments were developed recently and have not been established in the literature. Although currently used generic and activity-level measures have limitations, as well, they should be considered, depending on the specific goals of the study. Additional research is needed to assess the properties of these measures fully when used to evaluate patients with FAI.Patient-reported outcome measures (PROs) often are the preferred primary outcome metrics to assess symptom modification in clinical trials. They are an important component of outcomes assessment because they represent the patient's health status as assessed by the patient, without interpretation of the healthcare provider. 1 To be useful, PROs must be reliable, valid, responsive, and representative of the patient population of interest.This article provides recommendations for the PROs to be used in clinical trials investigating the efficacy of treatments for femoroacetabular impingement (FAI). It describes and provides quality ratings for disease-specific PROs developed for young-tomiddle-aged adults with hip pain and dysfunction and presents common instruments to assess generic quality of life (QOL) and physical activity levels. Perspectives on future relevant directions and methodologies, such as computer-adaptive testing (CAT), are discussed, as well. (Table 1). In this review, however, we used stringent criteria for instrument selection and therefore only those diseasespecific PROs are included in which content validity was ensured through input from patients of similar age, sex, and activity level who had experienced symptoms and limitations due to FAI. Accordingly, we excluded instruments such as the Hip Outcome Score that although specifically developed and validated for impingement patients undergoing hip arthroscopy did not involve the patient opinion in the developmental process. Therefore, based on previous reviews of the literature 10-13 and the authors' collective knowledge, focus was placed on three disease-specific PROs that explicitly included young to middle-aged adults in the development of the measures.Each PRO described below is patient administered, with a user-friendly format that requires ≤10 minutes to complete. All of them are self-explanatory and can be administered in the waiting room or mailed so that the patient can complete it at home. The quality of each PRO was assessed using the COnsensus-based Standards for the selection of health Measurement I...