The aim of this study was to evaluate the effects of different surface treatments on the bond strength of fiber posts into root canal. Forty-four recently extracted human mandibular premolars were instrumented by K3 TM rotary system. The root canals were filled with gutta-percha and Sealapex TM sealer. Post spaces were prepared, and root canals subjected to one of the following four surface treatments: irrigation with 0.9% sodium chloride (NaCl), 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine gluconate (CHX), or 17% ethylenediamine tetraacetic acid (EDTA). Fiber posts were cemented with self-adhesive resin cement RelyX TM (Unicem). From the coronal part of each root, three slides with 1 mm in thickness were obtained. A push-out bond-strength test was performed with the aid of a universal testing machine at a crosshead speed of 0.5 mm/min. Data (in MPa) were subject to statistical analysis by two-way ANOVA and post hoc Tukey's test (p < 0.05). Results revealed no significant differences between the different chemical solutions used as surface treatments before the luting procedure. EDTA elicited the highest bond strength. The results also showed that surface treatment with NaOCl or EDTA increased bond strength to dentin, as compared with the control group. The bond strength of fiber posts to root canal dentin was not significantly affected by surface treatment with 2.5% NaOCl, 2% CHX solution, or 17% EDTA.Keywords: Endodontics. Bonding agents. Dentin. How to cite this article: Cintra LTA, Batistella AR, Marson FC, Archangelo CM, Gomes-Filho JE. Effect of different surface treatments on the push-out bond strength of iber posts into the root canal.