Objective: To evaluate the mechanical properties of a glass hybrid (GH) restorative system (EQUIA Forte/GC) and compare it with a microhybrid composite (G-aenial Posterior/GC) by compressive strength (CS) and fracture resistance (FR) tests. Materials and Methods: Cylindrical specimens were subjected to a CS test (n = 12). There were about 48 mandibular molars were used for a FR test and divided into four groups: Group 1 (positive control), sound teeth; Group 2 (negative control), extended size Class 2 cavities prepared on the mesial surfaces of teeth; Group 3, extended size Class 2 cavities restored with a composite; and Group 4, extended size Class 2 cavities restored with GH. Specimens were subjected to loading until a fracture occurred. Data were analyzed statistically (a = 0.05). Results: The fracture modes were examined by scanning electron microscope (SEM). The CS values of the composite and GH were 278.20 17.34 MPa and 164.62 25.72 MPa, respectively (P < 0.05). No differences were observed between the FR of restored groups (P 0.05). Conclusions: The GH exhibited sufficient mechanical properties as a restorative material, and could be preferred for extensive caries lesions on posterior teeth.