The present study was carried out to evaluate the wear resistance of microhybrid resin composite versus nanofilled composite via two body wear testing whether immediately or after storage in artificial saliva for specific periods. Materials and Methods: A total of 120 specimens were done and classified into two main groups, 60 specimens according to the used material, A1: Micro-hybrid & A2: Nano-filled resin composites. Each group will be further subdivided into two groups of 30 specimens according to wear time, B1: 2 minutes & B2.: 4 minutes. They were further classified according to storage period, into C1: after 1 day & C2 : after 1 month and C 3 after 3 months. The thickness of the specimen was measured using a digital micrometer before and after wear test. Results: there was significant difference between wear resistance of microhybrid resin composite and nanofilled resin composite. Conclusions: Microhybrid composite showed higher wear resistance than nanofilled composite. Wear is time dependent.