The purpose of this study was to compare the fracture resistance of immature roots having apical plug with Portland cement (PC) together with obturation using (i) Zinc Oxide based sealer (ii) Epoxy resin based sealer used with lateral compaction of gutta-percha (iii) Total obturation with Portland cement. Twenty five single rooted teeth were randomly assigned into three experimental groups according to the filling material and one control group. The control group was subdivided into a negative control with unprepared teeth and a positive control with unobturated immature teeth. Teeth in all groups except the negative control were prepared to stimulate immature roots. Root ends in the three experimental groups were filled with a 4 mm barrier of PC. Then the canals were obturated using the three selected materials. Fracture resistance testing was performed using a universal testing machine after embedding teeth in artificially prepared sockets. Fracture load value was measured in Newtons (N) and the fracture pattern was determined. Results indicated that ZnO/E exhibited the highest mean fracture load values, followed by PC, then Ez-Fill. The positive control group showed the least mean fracture values. However ANOVA test revealed no significant differences between all groups (P=0.06). It was concluded that, the use of ZnO/E, or Ez-Fill with gutta-percha core material, as well as, total filling with PC compensated the reduced strength from the lost dentin substance in the simulated immature teeth with PC apical plug.