Background: Patellofemoral pain (PFP) has a debilitating effect on sufferers, daily lives by reducing their ability to perform sporting and work related activities pain free. The Kujala Patellofemoral Disorder Score (KPS) was particularly designed and developed for the assessment of patients having anterior knee pain as well as patellofemoral conditions. Objective: The purpose of the study were to culturally translate and validate the Arabic version of KPS (and evaluate the test-retest reliability, internal consistency, construct validity ceiling or floor effects of this instruments) in Egyptian patients with PFP to measure the physical function and to ensure better care delivery. Methods: Three expert panels (each consists of nine experts) and 46 patients with PFS participated in this study. Forward translation, development of preliminary initially translated version, backward translation, and development of the pre-final version and testing of pre-final version using experts then testing of the final version on patients were done. Clarity index, expert proportion of clearance, index of content validity, expert proportion of relevance, descriptive statistics, missed item index, time taken to answer the scale, Cronbach’s coefficient alpha and Spearman’s rank correlation coefficients were used for statistical analysis. Results: The scale index of clarity equaled 89%, while The S-CVI equaled 86.5%. With regard to internal consistency, the Cronbach's alpha equaled 0.598 (range from 0.487 to 0.660). In addition, the Spearman’s rank correlations were moderate to strong in the majority of items. Conclusion: The Arabic KPS is a valid and reliable tool and is comparable to the original English version and other translated versions.
