The purpose of this study was to evaluate Moyer's prediction chart, by application of this chart on Egyptian sample, and to develop an Egyptians prediction chart based on the Egyptian background. 318 upper and lower study casts of patients ranging in age between 13-18 years were collected from the records of Orthodontic department Faculty of Oral and Dental Medicine, Cairo University. The misiodistal widths of the upper and lower incisors, and the upper and lower canine and premolars were measured by boley gauge graduated to the nearest 0.1 mm. Also the perimeters of the upper and lower arches were measured between the mesial surfaces of the first permanent molars along the arch, by the segmented technique. From the results of this study the following conclusion can be drawn: 1. Moyer's prediction chart was found to be not applicable to the Egyptian sample under the 75% probability level. 2. The Moyer's chart overestimated the misiodistal widths of the upper and lower canine and premolars. 3. the probability confidence levels of Moyer's chart (5-35%) were found to be the nearest prediction figures to the Egyptian sample.