Background Evaluate the discrepancy in diameter and taper between adapted gutta-percha cones for TruNatomyTM 26.04 (TRU04), RotateTM 25.04 (ROT04) and 25.06 (ROT06) systems and their reference files. Material and Methods A sample of 60 gutta-percha cones and 15 rotary files was selected and divided into three groups (TRU04, ROT04, ROT06). Each group consisted of 20 cones and 5 corresponding files. They were observed under an optical microscope at x20 magnification and images of all observations were obtained. Diameters were measured with a digital ruler calibrated at 3 levels: D1, D3, D16 (mm from tip). The taper of each system of cones and files was calculated, The percentage of discrepancy between the taper of each file system and its corresponding gutta-percha cone was calculated. Results The percentage of discrepancy between the diameter of the tested gutta-percha cones and their corresponding files varied from -7% to 21%. The smallest dimensional discrepancy between gutta-percha cone and corresponding file was found at D16 in TRU04 group. The tapers of the gutta-percha cones vs their respective files were: 2% vs 3% (TRU04), 4% vs 5% (ROT04), and 6% vs 5% (ROT06). The highest discrepancy was observed at D16 in ROT06 group. The global taper discrepancy between gutta-percha cone and its corresponding file was negative in TRU04 and ROT04 groups. Conclusions The taper and the diameter at D1, D3, and D16 differed between all of the tested gutta-percha cones and their corresponding files. TruNatomy 26.04 files and its adapted gutta-percha cones exhibited the least discrepancy. Key words: Corresponding gutta-percha, rotary file, taper, TruNatomy, Rotate, standardization.