The current research aimed to construct a scale of functional efficiency of the upper extremity in children with cerebral palsy and verify its psychometric properties. To achieve this goal, the researcher used the experimental method, and a random sample of children with cerebral palsy in Cairo Governorate was selected, with a size of (51) children. The scale of functional efficiency of the upper extremity was applied, consisting of (162) items, distributed over the nine sub-dimensions. The significance of the internal consistency indicators of the scale was calculated by calculating the correlation coefficients between the scores of each phrase of the scale and the total scores of the dimension to which it belongs, and between the dimensions as well and the scale as a whole and its significance level. The significance of the scale's stability indicators was calculated using Cronbach's alpha and Spearman/Brown's split-half method. The factorial validity of the functional efficiency scale for the upper extremity was also calculated. The results showed that the psychometric properties of the functional efficiency scale for the upper extremity in children (with validity and stability) were available to a high degree, and therefore it is suitable for application by those working in the field of special education, especially with children with cerebral palsy. Based on the literature and results of the research, a set of recommendations and proposals were developed.