Background: There is no valid and reliable instrument thatevaluates injury severity and treatment effects for medial tibialstress syndrome (MTSS) patients.Objective: The aim was to generate items for the MTSS score, anew patient-reported outcome measure for patients with MTSS.Methods: The authors consulted experts in the field of MTSS togenerate items that measure the severity of MTSS and to reachconsensus on the relevance of items for the MTSS score. Thisresearch consisted of a pilot study and two Delphi rounds. TheDelphi approach entails the consultation of experts about a topicfor which no evidence is available during which consensus issought on this topic. Additionally, 20 MTSS patients appraisedthe MTSS score on readability and comprehension.Results: Nineteen experts consented to participate, 13 of whomreached consensus. Generated items address the followingdomains: ‘limitation in sporting activities’, ‘pain while performingsporting activities’, ‘pain while performing activities of dailyliving’ and ‘pain at rest’. Patients with MTSS confirmed the goodreadability and comprehension of the items.Conclusion: This study supports the importance of items in theaforementioned domains while evaluating treatment effects inpatients with MTSS.