The aim of the present study was to assess the degree ofmicroleakage observed when using two different post-endodontic reconstruction systems; this was achieved assessing penetration of a dye along restorations performed with endodontic posts anddual-cure resin cements. For the present study, 30 extracted, single rooted premolars were used. Root canal treatment was performed onthe teeth which were later stored in bi-distilled water at 37 oC. Teeth were randomly allotted to three groups, all groups were comprised of10 teeth. In two groups, post cementation was performed using the systems RelyX Fiber Post (3M ESPE dental products) and Parapost (Coltene-Whaledent). Samples were subjected to thermo-cyclingand later immersed in methylene blue for seven days at 36 oC. Afterthis, samples were subjected to a diaphanization process and werethen analyzed under a microscope; penetration in millimeters wasthus obtained. Results revealed that teeth treated with Parapost system exhibited lesser microleakage. Control group experiencedthe greater amounts of microleakage. Statistical analysis conducted with Donett test showed statistically signifi cant difference between Parapost and RelyX systems. Conclusion: Parapost reconstruction system (Coltene-Whaledent) with acid-etch technique exhibitedlower microleakage values. Results were statistically significant when compared to those obtained with the RelyX reconstruction system (3M ESPE dental products).