Aim: The aim of this in vitro study was to evaluate the effect of multi-stage polishing systems on the surface roughness of three different composite resins used in the posterior region. Material and Methods: The composite resin groups tested in the study were as follows: Group I: nanohybrid-incremental composite (Filtek Ultimate, 3M ESPE); Group II: nanohybrid-bulk fill composite (Tetric EvoCeram Bulk Fill, Ivoclar/ Vivadent); Group III: packable composite (Solitaire 2, Heraeus Kulzer). Twenty-four samples of each material were prepared in a Teflon mold using Mylar Strip (10mm diameter,2mm height). Samples were kept in distilled water for 24 hours at 36 °C before testing. Ra value was obtained by measuring at three different points from each sample with the Surface Roughness Tester (Mahr Perthometer S4P). After finishing procedure, they were randomly divided into 2 subgroups according to polishing procedures(n=12): (a)OptiDisc (Kerr) /Hiluster Plus polishing system (Kerr), (b) SwissFlex (Coltène/Whaledent) /Hiluster plus polishing system (Kerr). Following finishing and polishing, surface roughness of the samples was measured. Sample surfaces were analyzed by scanning electron microscopy. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests (p=0.05). Results: The smoothest surfaces were obtained with Mylar strip in all study groups (p=0.000). After finishing and polishing, there were significant differences between groups (p=0.005). Among all groups, the highest roughness value was seen in Group III. Among the polishing systems, only a statistically significant difference was observed in roughness values of Group I (p =0.000). The Ra values of the samples applied with OptiDisc polishing system were found to be higher than SwissFlex. Conclusion: It was concluded that the nanohybrid composite materials used in the posterior area are polished better than condensable composites. It has also been found that a single polishing system does not produce the same surface quality for all composite resins.