A prospective study was conducted in which 21 patients received a mandibular implant-supported overdenture. Eighty-four ITI screw-type implants were placed in the interforaminal area of the mental symphysis (4 implants per patient). Immediately after implant placement, a U-shaped gold or titanium bar was fabricated and implants were loaded with an implant-retained overdenture. Of 21 patients treated, 19 were followed for a minimum of 25 months to a maximum of 60 months, with a mean follow-up of 37 months. Two patients dropped out during the follow-up. The overall failure rate of implants (according to Albrektsson criteria) was 4% (3/76 implants), but all implants, bars, and prostheses remained in function. Results from this study demonstrated that the success rate for immediately loaded mandibular implants is similar to that obtained in cases of delayed loading, after osseointegration has taken place. This method shortens dental rehabilitation time with relevant satisfaction for patients. Keywords: complete overdentures, dental implants, edentulous jaw, immediate implant loading, mandibular prosthesis, osseointegration, prospective study