AIM: Investigation and evaluation of Pont's and Korkhaus indices of dental arch dimensions and comparison with Iranian adolescents' measurements.STUDY DESIGN: Descriptive and cross-sectional study.TIME AND PLACE OF STUDY: Department of Orthodontics, Shaheed Beheshti Medical Sciences University, School of Dentistry, Tehran, Iran, 2002.MATERIAL AND METHOD: Upper dental casts of 80 individuals with Class I occlusion (40 boys and 40 girls, mean age 14.11±0.82 years) were used.PRINCIPAL MEASUREMENTS: Seven variables were investigated and the results were analyzed using the statistical software SPSS and Excel. To determine correlation between mesiodistal width of teeth and dental arch width "Pearson Correlation” analysis was used. RESULTS: The results were as the followings: (a) There was a significant difference between anterior arch width of Iranian children (1.27±1.30) in comparison to suggested standard value (2.13±1.93) (p<0.001). (b) There was also a significant difference between posterior arch width (1.04±0.54) and of the corresponding standard value (1.52±1.22) (p<0.001). (c) The standard for anterior arch length (0.69±1.42) was significantly different from the suggested value (0.98±0.47) (p<0.001). (d) While Tonn’s formula predicated the sum of upper incisors (SUI) value as 1.42±1.21, in this study it was found different (1.23±0.62). However, this difference was not statistically significant. CONCLUSIONS: According to the results of this study, maxillary dental arch dimensions of Iranian populations are different from the standard values published in major orthodontic references.