Objective: This in vitro study presents an investigation focusing on the retention of zirconia and glass fiber posts. The aim of the study was to evaluate the influence of four dualcured resin cements - two self-etching/self-adhesive systems (Panavia F 2.0, RelyX Unicem) and two cements by classical phosphoric acid application (Bifix QM, Nexus 2) - on the retention of a prefabricated tooth-colored post system (Cerapost, Dentinpost). Some specimens of zirconia posts received surface treatments by sandblasting. Method and materials: 120 freshly extracted incisors and canines were treated endodontically. The root canals were filled with laterally condensed gutta-percha and sealer. The teeth were assigned to one of 12 groups, each containing 10 specimens: sandblasted/nonsandblasted zirconia post and nonsandblasted glass fiber posts were cemented with each dual-cured resin cement. Following water storage at 37 degrees C for 24 hours, retention was determined by tensile tests. The specimens were also quantitatively analyzed under a scanning electron microscope. Results: The retentive strengths of zirconia posts cemented with Panavia F 2.0 and glass fiber posts cemented with RelyX Unicem were significantly increased compared to those cemented with all other resin cements of the investigation. Conclusion: Dualcured resin cements can be used basically for zirconia and glass fiber posts. Choice of resin cement was critical for both types of posts. Surface pretreatment by sandblasting had no significant influence on the retention of zirconia post. Dual-cured, Self-etching and selfadhesive resin cements can be recommended for application of zirconia and glass fiber posts.