The aim of this study was to clarify the effect of the surface roughness of various metal wires on the fracture resistance of the acrylic test specimens. The number of test groups compared were 16, and there were 30 test specimens in each group. The investigation showed that the surface roughening of the metal wires used to reinforce acrylic resin denture base material increased the fracture resistance of the test specimens. The best results were achieved by sandblasting. The differences in resistance were also statistically significant.