True bilateral body symmetry is largely a theoretical concept that seldom exists in living organisms. Right-left differences occur everywhere in nature where two congruent types are present.Symmetry can be defined as equality or correspondence in form of parts distributed around a center or an axis, at the two extremes or poles, or on the two opposite sides of the body.Clinically, symmetry means balance while significant asymmetry means imbalance. The dentofacial asymmetry is considered a major etiological factor of malocclusion. Many factors as congenital malformations, digital habits, interproximal caries and premature extractions can influence dental arch asymmetry. Early recognition and treatment of dental arch asymmetries could minimize the need for complex treatment mechanics. However, there is a paucity of data in the literature that addresses the issue of dental arch asymmetry in the mixed dentition. Accordingly, the purpose of this study was to quantify and describe dental arch asymmetry in a group of Egyptian children in the mixed dentition by using a computer aided-system.