The purpose of this study was to detect the correlation between age and gender with flat foot deformity in obese children. One hundred fifty children ranged in age from 8-14 years participated in this study. They were selected according to body mass index to be obese children, then they were divided according to gender into two groups, group I and group II (75 boys and 75 girls), then each group divided according to age into equal three sub groups (from 8-10 years, from 10-12 years and from 12-14 years) each sub group included 25 children. Evaluation for each child was done using the Foot Posture Index-6 and foot print. The Foot Posture Index-6 was used to asses foot posture, while foot print was used to measure Stahili planter arch index. The results of the study showed that there were significant statistical differences in Foot Posture Index-6 score and arch index between group I (boys) and group II (girls), while there were no significant statistical differences in Foot Posture Index-6 score and arch index in the subgroups according to age. It was concluded that there was significant positive correlation between gender and incidence of flat foot, while there was no significant correlation between age and incidence of flat foot.Key words: Flat foot, obese children, stahili planter arch index, foot posture index-6 INTRODUCTIONThe foot has three arches; the medial longitudinal arch, the lateral longitudinal arch and the transverse arch. The medial longitudinal arch is the highest and most important of the three arches. It is composed of the calcaneus, talus, navicular, cuneiforms and the first three metatarsals. The lateral longitudinal arch is lower and flatter than the medial longitudinal arch. It is composed of the calcaneus, cuboid, the fourth and fifth metatarsals. The transverse arch is composed of the cuneiforms, the cuboid and the five metatarsal bases. The arches of the foot are maintained not only by the shapes of the bones as well as by ligaments. In addition, muscles and tendons play an important role in supporting the arches (George et al., 2009).Deformities of the lower extremities are very frequent in children and most of the time these conditions are physiological and do not need any treatment. Ninety percent of clinic visits for foot problems are due to flatfoot (FF) (Fabry, 2010).The definition of flat foot is not standardized, nevertheless but the height of the medial longitudinal arch is the principal parameter to be observed and measured (Villarroya et al., 2009).