Several sinus floor elevation procedures for implant placement have been introduced. The present study aimed to evaluate the implants placed with Platelet-rich fibrin (PRF) alone in atrophic posterior maxillae and survival rates and the potential factors associated with implant loss. This retrospective study evaluated 71 implants in 34 patients after 1-7 years? follow-up time. Statistical models were used to determine the implant survival and the potential factors associated with loss. Overall, 7 implants were lost, and the cumulative survival rate at 7 years by implant-based and patient-bases analyses were 85.5% and 85.7%, respectively. The mean residual bone height (RBH) was 4.26 mm. The implant survival rate was significantly lower at RBH < 4 mm than RBH ? 4 mm. This retrospective study showed that sinus floor elevation with PRF alone could be applied in cases of lower RBH. However, it should be carefully performed in cases of RBH < 4 mm before surgery.