Purpose: This study aimed to compare NiTi rotary systems of different wires namely; EdgeFiles, Profile GT series X (GTX) and ProTaper (PT) in terms of: canal transportation and centering ability. Materials and Methods: One hundred and twenty extracted human mandibular first molars were selected and randomly divided into two main groups (I&II) according to the ranges of curvature (60 teeth each), where group I: samples with 25º-40º range of curvature and group II: samples with 45º-60º range of curvature. Each group was subdivided into four subgroups according to the NiTi rotary system (15 teeth each): subgroup A: ProTaper, subgroup B: Profile GT Series X, subgroup C: EdgeFile X3 and subgroup D: EdgeFile X5. The root canals were scanned by i -CAT CBCT scanner before and after instrumentation at 3, 5 and 8 mm levels from the apex, to assess the canal transportation and centering ability. Results: The EdgeFile system produced the least canal transportation and remained more centered around the original canal than the other systems. While, PT system produced significantly the highest canal transportation and the least centered canal preparation than other systems. Conclusions: EdgeFile systems showed superior performance regarding maintenance of the original root canal curvature and centering ability than do other systems.