Objective A retrospective study was performed to observe clinical outcomes of dental implants placed in augmented maxillary sinuses using an osteotome or a lateral approach technique with synchronous or delayed implant placement. Study design A total of 61 patients were enrolled in the study. The distribution and frequency of sinus augmentation techniques and implant placements were evaluated according to the implant site and Cawood-Howell classifications. The implant survival rates were assessed clinically and radiographically over a minimum of 3 years of follow-up. Results The number of implants placed was fewer in the molar region compared with the premolar region and was independent of the surgical techniques used. Significantly fewer implants were placed in implant site class D and Cawood-Howell class V. Optimal survival rates were evident in all groups, with no significant changes. Conclusion The most predictable region for sinus augmentation with simultaneous implant placement was the maxillary premolar area. All 80 implants were successful using either osteotome or lateral approaches to augment the maxillary sinus floor.