Objective: To determine the cross-cultural validation and test-retest and inter-rater reliability of the Persian translation of Parent version of the Gross Motor Function Classification System (GMFCS) for children with cerebral palsy (CP).

Materials & Methods: 90 Children (2 to 12 years, mean age 6.6 years 57boys, 33girls) with various types of CP were classified according to GMFCS by parents.After the forward and backward translation procedures, face and content validity and test–retest reliability between parents and inter-rater reliability between parents and therapists was assessed using the intra-class correlation coefficient (ICC) and the weighted kappa coefficient.

Results: The ICC was 0.92 and showedexcellent agreement and the weighted kappa coefficient was 0.61 andshowed good agreement. The inter-rater reliability was also high the ICC was 0.88 with excellent agreement and the weighted kappa coefficient was 0.68 and with good agreement.

Conclusion: The Persian translation of Parent version of GMFCS is found to be valid and reliable, and is suggested to be appropriate for the assessment of gross motor function within the Iranian population.