Pediatric endodontics deals with the management of pulpally involved primary and young permanent teeth in children. Maintaining the integrity and health of the oral tissues is the primary objectives of pulp treatment. It is desirable to attempt to maintain pulp vitality wherever possible. In permanent teeth, definitive rules for successful endodontic therapy have been established such as compact obturation and apical/coronal seal. In contrast, because of difficulties in estimating the exact root canal length there are no definitive rules for successful endodontic therapy.Root canal length determination is an important step in root canal therapy. Correct working length determination is one of the main factor leading to success in root canal treatment. Endodontic anatomy of primary teeth, in particular of molars is difficult to predict because of the resorption, Shape, dimension and position of the root apex are often continuously altered. The purpose of the present study is to compare the working length determined by digital radiography and Apex locator with that of conventional radiographic method for accuracy.