Aim: The aim of this study was to measure the retentive forces of glass fiber post using different resin cements and core material with different adhesive systems. Materials and methods: conventional resin cement, a self-adhesive resin cement, one type of core material (Flow type), one type of fiber post and two types of commercial bonding agents (etch and rinse and self- etch adhesive system) were tested in this study. The pull out test was used for testing the retentive force (n=50).The specimens were divided into groups according to the type of the cement and the adhesive system used. Data were statistically analyzed using two-way Analysis of Variance and Tukey’s post-hoc test. Results: Resin core material with total etch technique showed the significantly highest mean retentive force values to glass fiber post followed by the use of selfadhesive cement. Conclusions: Resin core material (flow type) with the total-etch adhesive system can be used as a post luting agent and as a core at the same time as it satisfies the concept of the monoblock unit. The use of self-adhesive resin cement is suggested for cementation of fiber post rather than the conventional types of resin cement.