OBJECTIVE The aim of this study was to evaluate the efficacy of autologous intraoral onlay bone grafting (OBG) in correlation with long-term survival rates of dental implants placed in the augmented bone. METHODS A retrospective study was conducted on 214 patients who received a total of 633 dental implants placed in 224 autologous intraoral block OBG augmentations, combined with Bio-Oss - mixed with platelet-rich plasma (PRP) and covered by platelet-poor plasma (PPP) - as scaffold, with a follow-up time up to 137 months (mean 39.9 ± 30.9 months). RESULTS A total of 216 OBG cases were successful (96.4%), and most of the augmentations were uneventful (88.4%). Bone graft exposure was moderately associated with bone graft failure (χ(2)  = 3.76, p = .052). The healing period after implant placement was 4-6 months (mean 5.6 ± 2.56). The majority of the 591 implants survived (93.4%). The cumulative survival rate of the implants was 83%. CONCLUSIONS We suggest that augmentation of severely atrophied jaw bone through the placement of horizontal and/or vertical intraoral OBGs in combination with Bio-Oss saturated with PRP and covered by PPP should be considered a reliable, safe, and very effective surgical technique for obtaining high bone graft survival rate and high long-term implant survival rate.