Background <p>This study aimed to assess the effect of diode laser irradiation on pushout bond strength (PBS) of fiber post to root dentin using different resin cements.</p> Methods <p>This in vitro experimental study utilized 36 extracted single-rooted mandibular premolars. The samples underwent decoronation, root canal treatment, and post space preparation. Teeth were randomly assigned to four groups (<i>n</i> = 9 each): ((I) etch-and-rinse (ER) adhesive system and conventional resin cement, (II) diode laser irradiation (for simulated antimicrobial disinfection) + ER cement, (III) self-adhesive (SA) cement, and (IV) diode laser irradiation + SA cement. After 10,000 thermocycles (5–55&#xa0;°C), PBS was measured using a universal testing machine (Zwick/Roll, Ulm, Germany) at 0.5&#xa0;mm/min until failure. Cement-dentin interface morphology was qualitatively assessed via scanning electron microscopy (SEM; MIRA3 TESCAN, Czech Republic) on one specimen per group. Data were analyzed using one-way ANOVA and Bonferroni post-hoc tests (α = 0.05).</p> Results <p>Significant differences in PBS were observed among groups (<i>P</i> &lt; 0.001). Mean ± SD PBS values were: ER cement, 5.61 ± 1.47&#xa0;MPa; diode laser + ER cement, 5.75 ± 0.88&#xa0;MPa; SA cement, 7.75 ± 0.55&#xa0;MPa; diode laser + SA cement, 7.60 ± 0.97&#xa0;MPa. Pairwise comparisons showed SA cement groups had significantly higher PBS than ER cement groups (<i>P</i> &lt; 0.001 for both). Diode laser irradiation had no significant effect within cement types (<i>P</i> &gt; 0.05).</p> Conclusion <p>Resin cement type significantly influenced PBS, with SA cement outperforming ER cement. Diode laser irradiation had no significant effect on PBS.</p>