ABSTRACT Background: There is insufficient support for a permanent restoration in endodontically treated teeth with significant tooth structural loss. It's critical to preserve the apical seal when repairing them with post and core. Aim: Apical leakage assessment following both delayed and instant postspace preparation utilizing different root canal sealers. Materials and Methods: The roots of forty single-rooted teeth were biomechanically shaped, while using gutta percha for obturation, and sealed with AH Plus (Group A, n = 20) and Sure-Seal root canal sealer (Group B, n = 20) after being decoronated. A and B Groups were further separated as A1 and A2 and B1 and B2, respectively. Postspace was created straightaway for A1 and B1. After one week of preservation in physiologic saline, the post space for A2 and B2 was created. Rhodamine B dye was applied to the samples for 48 hours, after which they were cut lengthwise to examine dye penetration along the radicular dentinal wall via a stereomicroscope. The penetration of dye was linearly calculated, and then subjected values were analyzed with t-test statistical analysis and one-way analysis of variance Results: The comparative variance between Group A (0.9 mm) and B (3 mm) proved to be statistically significant (P 0.001). Though, no statistically relevant difference between the subgroups for delayed and immediate post space preparation (B1 = 2 and B2 = 3 ; A1 = 0.9; A2 = 1, P 0.001). Conclusion: As compared to Sure-Seal root canal sealing material, AH Plus sealing material shown less leakage. Timing for making postspace has no effect on apical leakage, since the difference in leakage values between the delayed and immediate post space preparation groups was not statistically relevant.