Background: The effect of the type of implant superstructure on oral health-related quality of life (OHRQoL) among edentulous patients remains controversial. Purpose: The purpose of this study is to investigate the association between the type of implant superstructure and OHRQoL. Materials and Methods: Seventy-two completely edentulous patients who received implant fixed complete dentures (IFCDs) or implant overdentures (IODs) were administered the Oral Health Impact Profile (OHIP) questionnaire during the post-treatment maintenance period. The OHIP summary score, as well as the four dimension scores, were calculated to evaluate OHRQoL. Results: The mean OHIP summary score for the IFCD group tended to be lower than that for the IOD group, but this difference was not statistically significant (19.9 ± 21.9, 22.8 ± 18.2, respectively; P = .57). However, a significant group difference was found in the four dimension scores (P < .01), with the OHIP item scores representing masticatory function being significantly lower in the IFCD group than in the IOD group (P < .05). Conclusions: Our results suggested that patients with an IOD exhibited comparable OHRQoL to those with an IFCD, with the exception of perceived masticatory function.