Aim: To assess the effectiveness of the Rogin multiple NiTi rotary file system compared to the Hyflex EDM single rotary file system in removing root canal filling material during root canal retreatment. Materials and methods: Thirty human permanent mandibular premolars with single root canals were mechanically prepared with ProTaper Next files up to X2 (25/06) till full working length. Then root canals were obturated using the continuous wave of compaction technique with gutta percha and AH Plus sealer. After one week of incubation, samples were randomly allocated into two groups according to retreatment file systems as follows; Group I: retreatment was performed by Rogin multiple retreatment file system, Group II: retreatment was performed by HyFlex EDM single file system. After retreatment samples were vertically split into two halves and digital images were captured by a digital camera mounted on a stereomicroscope at 10 x to be analyzed by image analysis software to calculate the percentage of residual filling material. Results: There was no statistically significant difference between the two groups in coronal (p=0.280) and middle thirds (p=0.180) but in the apical third; group I showed a higher statistically significant percentage of residual filling material than group II (p=0.001). Conclusion: Neither of the systems used was able to completely remove root canal-filling material and the Hyflex EDM single file system performed better in the apical third.