Purpose: Implants can be inserted simultaneously during sinus floor elevation (SFE), or 6 months later, for posterior maxillary rehabilitation. The residual bone height (RBH) is a major factor that affects the type of surgical procedure that will be performed. The aim of this study was to compare the survival rates of implants inserted during one-stage SFE with two different RBHs ( 5 mm and ≥ 5 mm). Materials and Methods: This study consisted of implants inserted into an RBH of either 5 mm or ≥ 5 mm, and the survival of the implants was assessed according to the clinical symptoms of the patients: pain or tenderness during function (or spontaneously), mobility, depth of probing, exudation history, and radiographic bone loss at the final follow-up appointment. The survival rates of the two groups were statistically compared using the Fisher exact test. Results: Fifty-nine consecutive patients (29 women and 30 men) undergoing a onestage sinus elevation procedure simultaneously with implant insertion were included in this study. Fifty-one implants were placed in the study group (RBH: 1 to 4.9 mm), and 31 implants were placed in the control group (RBH: 5 to 8 mm). The survival rate of the implants in the study group was 94.2% at the 5.4-year follow-up and 95.8% in the control group at the 7.9-year follow-up. There was no statistically significant difference between the groups in terms of the implant survival rate (P = .785). Conclusion: The results of this study suggest that SFE with simultaneous implant placement in patients with an RBH 5 mm can be accomplished, and that the survival rate is similar to that of the one-stage SFE protocol with an RBH of > 5 mm. Keywords: atrophic maxilla, lateral sinus elevation, one-stage sinus elevation, sinus floor augmentation, sinus floor elevation