Restoration of teeth affected by early childhood caries represents a challenge to pediatric dentists. The aim of this study was to compare between different techniques used to increase retention and resistance of composite crown restorations in badly decayed primary incisors. Subjects and Methods: Fifty-three badly decayed primary maxillary incisors were divided to four groups and treated using either four undercuts, mushroom undercuts, glass fiber posts or fiber reinforced composite posts and restored coronally using composite restoration. Finite element analysis was also used to compare between the groups. Results: There was no statistically significant difference between the four groups. The fractures in the posts groups were in the form of fracture of part of the restoration while in the undercuts group fracture was in the form of whole crown fracture. Also there was no significant difference in FEA results. Conclusion: Composite resin crowns can be used to restore badly decayed primary anterior using posts and undercuts to increase resistance and retention.