Evaluate push out bond strength (PBS) of endodontic obturation materials after washing by NaOCl, EDTA, and MTAD. Materials and methods: 30 mandibular premolars were utilized. Root canal instrumentation of all samples was achieved by ProTaper universal files to size F4. Samples were distributed to 3 groups; each group involved 10 samples as the following: Group1- samples were lastly washed by 5 ml of 5.25% NaOCl for 5 minutes. Group2- samples were lastly washed by 5 ml of 17% EDTA for 5 minutes. Group3- samples were lastly washed by 5 ml of MTAD for 5 minutes. All samples were filled by single cone technique with AH Plus sealer, and F4 ProTaper gutta-percha cone. 3 sections of 2 mm thickness were transected from every sample at 3, 7, and 11 mm from root apex, which represented apical, middle, and coronal sections consecutively. PBS was tested by universal digital testing device. Failure modes were assessed by stereomicroscope at 40 X magnification. Lastly, collected data was analyzed statistically. Results: MTAD group revealed significant greatest mean of PBS followed by EDTA group, and NaOCl group revealed significant least mean of PBS. In all groups, greater mean of PBS was in coronal section followed by middle section while, lesser mean of PBS was in apical section though, the differences among them were not significant within the same group. Mixed and cohesive failures were most dominant modes of failure in MTAD, and EDTA groups. While, in NaOCl group adhesive, and mixed failures were most dominant. Conclusions: last washing with MTAD is better than that with EDTA, and NaOCl in terms of greatest PBS.