Background: To evaluate the mechanical and surface properties of two glass ionomer restorative systems (EQUIA Fil, Ionostar Molar) and a resin composite (Charisma Classic) after thermocycling. Methods: Twenty disk-shaped samples were prepared from each material in teflon molds according to manufacturer’s instructions. After the samples were stored in distilled water at 370C for 24 h, microhardness and surface roughness measurements were performed from each group and repeated after 5000 and 10000 thermocycling. Scanning electron microscopy examinations were also performed. The data were analyzed by using Wilcoxon signed rank and Bonferroni corrected multiple comparison tests. Results: EQUIA did not exhibit significant differences in its microhardness values after thermocycling (p>0.005). In contrast, Ionostar Molar and Charisma Classic exhibited statistically significant decreases in baseline microhardness after 5000 and 10000 thermocycling processes (both p<0.005). However, there were no significant differences between 5000 and 10000 thermocycling groups for Charisma Classic (p=0.007). Ionostar Molar exhibited no statistically significant differences between its surface roughness values before and after thermocycling groups (p=0.067). Similarly, there were no significant differences between baseline and 5000 thermocycling groups for EQUIA and Charisma Classic (p>0.05). However, a statistically significant increase was observed after 10000 thermocycles for both of these two materials (p=0.002 and p<0.001, respectively). Conclusion: The EQUIA and Ionostar Molar exhibited mechanical features similar to those of a resin composite, and thus, represent promising materials for permanent restorations