Purpose: This cohort study evaluated patient satisfaction for maxillary implant-retained overdentures (IODs) on two implants up to 4 years and assessed the treatment effect over time. Materials and Methods: Patients encountering problems with their conventional dentures were included and received maxillary IODs on two titanium-zirconium implants and ball anchors in the canine area. Patient satisfaction was assessed using the oral health impact profile (OHIP-20E) questionnaires both for dentures and IODs. Two months after insertion of IODs (baseline), the patients chose the preferred overdenture design with full or reduced palatal coverage. OHIP-20E questionnaires were followed according to the individual choice at 1 and 4 years, and outcomes were compared with baseline. Results: Sixteen out of 21 patients were evaluated at a mean follow-up of 4 years (range: 2.4 to 4.8 years). There was no significant difference in the OHIP domains for IODs at 1 year (OHIP__total__1y: 9.5, SD: 13.0) and 4 years (OHIP__total__4y: 14.2, SD: 19.1) compared with baseline (OHIP__total__BL: 12.4, SD: 14.7). Patients were most satisfied with social disability both for IODs (OHIP__BL: 6.0, SD: 7.6; OHIP__1y: 3.4, SD: 5.4; OHIP__4y: 5.7, SD: 9.5) and dentures (OHIP__CD__old: 28, SD: 29.7; OHIP__CD__new: 25.4, SD: 28.67). Patients were least satisfied with functional limitation both for IODs (OHIP__BL: 6.0, SD: 7.6; OHIP__1y: 3.4, SD: 5.4; OHIP__4y: 5.7, SD: 9.5) and dentures (OHIP__CD__old: 28, SD: 29.7; OHIP__CD__new: 25.4, SD: 28.67). Conclusion: Patient satisfaction with maxillary IODs on two implants did not change from baseline to 4 years and was high at 4 years of function. Keywords: dental implants, dental prosthesis, edentulous, implant-supported, jaw, maxilla, overdenture, patient-reported outcomes, patient satisfaction, quality of life