This study aims to evaluate the effects of Er:YAG laser irradiation under different power settings on the pull-out bond strengths of fiber-reinforced composite posts. The crowns of single-rooted 60 teeth were removed by separation and the root canals were cleaned and shaped. Root canals were filled and post spaces were prepared. Sixty fiber posts were divided into five groups according to surface treatment methods as follows: an untreated control group, a sandblasting-coated group, and three groups undergoing surface preparation with Er:YAG laser under three different power settings (150, 300, and 450 mJ at 10 Hz for 60 s at 100-mu s pulse duration). After root canal procedures, fiber posts were cemented to the root canal. After all of the specimens were set, pull-out tests were performed using a universal testing machine at a crosshead speed of 2 mm/min. The data were analyzed using one-way ANOVA and Tukey post-hoc test (p < 0.05). The pull-out strength values ranged between 5.26 and 6.76 Mpa. The lowest values were observed in the groups without surface treatment. Surface treatment applied by 4.5-W Er:YAG laser increased the pull-out bond strength compared to the control group (p < 0.05). 4.5-W Er:YAG laser irradiation increased the pull-out bond strength of fiber posts to resin cement.