Purpose: The aim of this randomized clinical trial was to compare the relative efficacy of mandibular overdentures retained by only two implants and a bar attachment with conventional dentures. Materials and Methods: Edentulous adults, aged 35 to 65 years, were randomly assigned to two groups that received either a mandibular conventional denture (n = 48) or an overdenture supported by two endosseous implants with a connecting bar (n = 54). All subjects rated their general satisfaction and other features of their original dentures and their new prostheses (comfort, stability, ability to chew, speech, esthetics, and cleaning ability) on 100-mm visual analogue scales prior to treatment and 2 months postdelivery. Oral health–related quality of life was also evaluated pre- and posttreatment. Results: Multiple regression analysis revealed that the mean general satisfaction was significantly higher in the overdenture group than in the conventional denture group ( P= .0001). Age, gender, marital status, and income were not significantly associated with ratings of general satisfaction. Furthermore, the implant group gave significantly higher ratings on three additional measures of the prostheses (comfort, stability, and ease of chewing; P< .05). Conclusion: A mandibular two-implant overdenture opposed by a maxillary conventional denture is a more satisfactory treatment than conventional dentures for edentulous middle-aged adults. Int J Prosthodont 2003;16:117–122.