recognized. Previous researchers have shown that there is an increase demand for orthodontic treatment; however those reports were limited to the districts where they were performed, and were affected by life style in these areas, however, none of these studies was performed in the western province. The aim of this study was to investigate the prevalence of malocclusion and arch form in the permanent dentition among Saudi Arabian patients in Jeddah, to serve as a database for more successful orthodontic treatment. Malocclusion was evaluated based on Angle's Classification, also arch form was studied based on Ovoid (average), Taper (narrow) and Square (broad) shape arches. The investigated sample was 84 males and 93 females with mean age of 15.3 and 15.0 year for males and females respectively. The results of the study indicated that among males Angle Class II is the most prevalent type. In the lower arch, Ovoid shape was the most prevalent arch form, while narrow shape was the most prevalent arch form in the upper arch in all subjects (percentage was higher in males). Dental midline shift and crowding were the most prevalent variables among malocclusal features especially in females