The objective of this study was to evaluate the treatment outcomes (implant survival, denture satisfaction, subjective chewing ability, oral function and quality of life) of oral cancer patients with implant-retained mandibular overdentures, in whom the implants were installed during ablative tumor surgery, up to 14years after placement of the implants.Edentulous oral cancer patients with the need for surgery and in whom prosthetic problems were expected after oncological treatment, were offered implant-based treatment in the mandibula. All implants were installed during ablative tumor surgery in native bone in the interforaminal area. The patients and implants were evaluated by clinical assessments and standardized questionnaires.Of the 181 patients that fulfilled the inclusion criteria, 165 patients were included. One hundred patients received postoperative radiotherapy. In total 138 patients were rehabilitated with an implant-based prosthesis (84%). Of the 528 placed implants, 35 implants were lost during the follow-up (overall survival rate=93.4%). Implant loss was higher in irradiated patients. Rehabilitation not depend on radiotherapy, type of reconstruction used during surgery or the number of implants placed. Irradiated patients reported lower scores on several items of the quality of life and oral functioning questionnaires. Patients not wearing the prosthesis had lower scores on oral functioning questionnaires and reported less chewing ability. The type of reconstruction used or the number of implants placed did not give different outcome of the questionnaires.It was concluded that oral cancer patients can benefit from implants installed during ablative surgery, with a high survival rate of the implants, a high percentage of rehabilitated patients and short time between surgery and prosthetic rehabilitation. Patients not receiving post-operative radiotherapy report a better oral function and more prosthesis-related satisfaction. When possible from a prosthetic point of view, two mandibular implants should be placed.