The aim of the study was to evaluate the topographic surface changes of regular and electropolished RaCe NiTi rotary instruments in as-received and after multiple sterilization cycles. In addition the cutting efficiency effect of bothtypes, electropolished and non-electropolished, after repeated sterilization was considered. Material and procedures A total of twenty four RaCe rotary NiTi instruments size 35, 0.06 taper, and 25-mm in length, electropolished (n=12) and non-electropolished (n=12) were used . The study was conducted into two parts; Part I topographic surface changes after application of 1, 3 and 6 sterilization cycles. Part II cutting efficiency of RaCe instruments according to the surface condition of each instrument, electropolished and non-electropolished. For part I sterilization cycle was performed at 1210C temperature, 15-psi pressure for 30-minutes.qualitative assessments according to topographic deviation were recorded by scanning electron microscope at x-100, x-500 magnification. For part II seventy-two human permanent teeth with single straight root were prepared manually by K-type instrument size #30 then RaCe NiTi file size #35 were used after application of 1, 3, and 6 cycles of sterilization. Variation in the measured weight loss determines the cutting efficiency of the used instrument. Results showed that after 1,3 and 6 sterilization cycle, Non–electropolished instruments showed statistically significant difference in their mean surface change %than electropolished ones in the all section; tip, apical, middle, and cervical. For cutting efficiency statistically ANOVA showed that Electropolishing, number of sterilization cycles and number of uses had a statistically significant effect on mean weight loss. On Conclusion Successive sterilization cause surface alteration on NiTi instruments, whether electropolished or non-electropolished and increase the cutting ability of both electropolished and non-electropolished instruments.