Stainless steel crowns are one of the most common useful devices for restoration of the primary teeth which are endodontically treated or involed with structural defects such as severe caries, hypoplasia and traumatic injuries. Beside its noticeable advantages, there are some problems(complications)that limit the indications and practical usage of these crowns.According to the standards suggested by American Academy of Pediatric dentistre (1987), absence of marginal adaptation and insufficient extension of the margins are the most important factors resulting in gingival inflammation and periodontal problems around the crowns. Some other complications such as impaction of adjacent to permanent teeth, corrosion of amalgam fillings adjacent the crowns and occlusal interferences may also be noticed when using these prefabricated crowns over primary teeth. In general we may suggest that if appropriate restoration of primary teeth using different operative techniques is possible, it is preferable not to cover them with S.S. Crowns and the use of these crowns must be limited to the cases in which there is no other way to restore the severely destroyed weakened tooth structure.Aim: The aim of this study is to characterize the possible complications of S.S. Crowns beside its various advantages and to insist on the restoration and build up fillings of the destroyed primary teeth using different operative techniques.