Purpose: The aim of the present study was to evaluate microleakage of cemented nickel Chromium and milled Titanium dowel systems cemented with three different luting agents. Materials and Methods: two types of metallic posts (milled Ti and custom made NiCr) and three types of luting cements (Adhesor, Ketac cem and Rely X Unicem) were used. A total of 30 sound upper central incisors were divided into two groups (15 for each post type). Each group was further subdivided according to type of cement used into three equal sub-groups (n=10 each). Sub group A: Posts cemented with zinc phosphate (Adhesor), Sub group B: Posts cemented with glass ionomer (Ketac cem), Sub group C: Posts cemented with adhesive resin cement (RelyX Unicem). All samplesreceived 500 thermal cycles between 5ºC ± 4ºC and 60ºC ± 4ºC and then were immersed in 0.5% solution leishman dye for 24 hours at room temperature. Results: showed no significant statistical difference between the two post materials. The statistically significant difference was found between cement groups. Conclusion: Type of dowel/core/crown (NiCr & Ti) has no effect on microleakage. The luting cement played an influencing important role on microleakage of dowels used. RelyX Unicem was the most appropriate cement for cementation of NiCr and Ti dowel systems in terms of microleakage. NiCr and Ti dowels should not be cemented with Zinc phosphate cements.