This study tested the effect on the fracture resistance of acrylic resin test specimens when different amounts of fibers were incorporated in the resin matrix. The fibers used included glass, carbon, and aramid fibers, with 30 test specimens of each concentration of fibers. Transverse sections of the specimens were studied by scanning electron microscope to establish how the fibers behave in the polymerization process. The results indicated that an increase in the amount of fibers enhanced the fracture resistance of the test specimens (p < 0.001). The SEM micrographs of transverse sections of test polymerized specimens revealed void spaces of different sizes inside the fiber roving.