Purpose: To investigate and compare the effects of several polishing systems and thermal cycling on the surface roughness and color change of various polymer-based CAD/CAM materials. Methods: Bar-shaped specimens (GC CeraSmart, CS; Lava Ultimate, LU and Vita Enamic, VE) were prepared. All specimens were polished with SiC papers. The specimens in Group A served as control and no additional surface polishing was applied. Final polishing was performed using diamond polishing paste (Diapolisher Paste) in Group B. In Group C, aluminum oxide abrasive discs (Sof-Lex XT Pop on) were used. Group D was polished with diamond impregnated spiral polishing system (EVE Diacomp Plus Twist). In Group E, polishing was done with rubber-based silicon abrasives (Polydentia). Thereafter, the specimens were submitted to thermal cycling. The surface roughness and color measurements were performed. Kruskal-Wallis and the Mann-Whitney U tests were applied for the evaluation of Delta E00 data. Ra data were evaluated using three-way ANOVA. Pearson's correlation between Ra and Delta E00 was further investigated. Results: Neither the CAD/CAM materials nor thermal cycling affected the Ra data (P>0.05). In contrast, significant difference was found among the polishing methods (P<0.001). On the other hand, VE showed the highest color change whereas LU showed the lowest (P<0.05). Additionally, the specimens in Group D exhibited significantly higher color change than other tested groups (P<0.05). A moderate positive correlation was seen between Ra and Delta E00 data of LU (rho = 0.390, P= 0.01).