Objective: The study was aimed at assessing by means of thin-slice push-out test, light and scanning electron microscopy, the interfacial strength and sealing ability of new self-adhesive resin cements when used to lute fiber posts into endodontically treated teeth. Methods: SFCem44 (3M ESPE, SFC), Maxcem Elite (Kerr, ME) and sET (SDI, S) were utilized in combination with RelyX Fiber Posts (3M ESPE). In each group 5 posted roots were used for push-out testing and 5 were processed for observations of interfacial morphology and nanoleakage under light microscope and scanning electron microscope. Five to six slices were obtained from each posted root. Between-group differences in push-out strengths were statistically assessed using One-Way Analysis of Variance and Tukey test for post hoc comparisons (p<0.05). Results: The interfacial strength achieved by SFC (9.32.6 MPa) was significantly higher than that of ME (6.72.7 MPa) and that of S (5.43.1 MPa), which were comparable to each other. Specimens luted with SFC showed lower interfacial nanoleakage than ME and S. Conclusions: SFC exhibited a significantly greater post retentive ability and provided a better marginal seal than the other new self-adhesive resin cements.