Resin cements are sometimes recommended to enhance the retention of posts in endodontically treated teeth. Many sealer cements used in endodontics contain eugenol, however, which has been shown to inhibit the polymerization of resins. The purpose of this study was to evaluate the effects of a eugenol and a noneugenol sealer cement on the retention of posts. Sixty extracted canines were divided equally into four groups. Each tooth received conventional endodontic therapy and was prepared to receive a post. Two sealer cements were used in obturation: one contained eugenol and one was eugenol-free. The posts were cemented with either zinc phosphate cement or resin cement. Each combination of sealer and post cement was tested for retention on an Instron testing machine. The type of sealer used had no effect on post retention with either cement. Post retention was significantly greater with the zinc phosphate cement than the resin cement.