Background: A core build-up is a restoration placed in a badly broken down tooth to restore the coronal portion. This facilitates restoration of the broken down tooth by means of extra-coronal restoration. Compressive and flexural strength of core materials is thought to be important because core usually replaces the large bulk of the tooth structure and must resist multidirectional forces. In this study, compressive and flexural strength of a newly introduced core material was determined and compared with conventional core materials. The purpose of the study was to evaluate and compare the compressive and flexural strength of Zirconia modified Glass Ionomer used as a core build-up material with other conventional materials. Methodology: Cylindrical specimens measuring 6mm in height and 4mm in diameter were prepared using machined aluminium mold. Ten specimens were prepared in each group. (Amalgam, Resin modified GIC, Light cured composite, Zirconia modified Glass Ionomer). Compressive strength was determined using a universal testing machine. The maximum load applied to fracture the specimen was recorded and compressive strength was calculated in Mega Pascal. Results: The mean compressive strength and flexural strength was significantly higher (p <0.05)in Glass reinforced composite group as compared to Zirconia modified Glass Ionomer, DPI alloy and Vitrimer, but no statistically significant difference was observed between Zirconia modified Glass Ionomer vs DPI alloy, Zirconia modified Glass Ionomer vs Vitrimer, DPI alloy vs Vitrimer. Conclusion: Within the limitations of this study, Glass reinforced composite had higher strength compared to the other three core build- up materials.