INTRODUCTION: Implant placement in the maxillary posterior alveolar ridge is often complicated by post extraction bone resorption, pneumatization of maxillary sinuses, and poor quality of alveolar bone. In these situations, the residual vertical bone height is reduced making standard implant placement difficult. Elevation of the maxillary sinus floor using the lateral antral approach is one possible solution. Palatal window osteotomy approach for maxillary sinus floor lifting is a new surgical technique used to increase vertical bone height prior to implant placement. OBJECTIVES: This study was designed for clinical evaluation of the maxillary sinus lifting technique using a palatal approach versus buccal approach. MATERIALS AND METHODS: this study was carried out as a randomized controlled clinical trial, the study sample included 14 patients. The sample was selected conveniently to fulfill a list of inclusion and exclusion criteria. All patients were divided into two equal groups, had gone maxillary sinus lifting together with implant placement, group1 :( study group) seven patients had sinus lifting through the palatal approach technique simultaneously with implant insertion. In group2 (control group) seven patients had maxillary sinus lifting using buccal antral approach technique simultaneously with implant insertion. Clinical and radiographic evaluation was done through 6 months postoperatively. RESULTS: Regarding postoperative clinical evaluation, group 1 was superior to that of group 2 in tissue management, because the vestibular anatomy in this group was not altered neither postoperative swelling occurred consequently nor disharmonious soft tissue scarring. Regarding the postoperative radiographic evaluation, group 1 was significantly increased in bone density around dental implants and less marginal bone loss postoperatively, however group 2 had higher vertical amount of bone gained around implants postoperatively. CONCLUSIONS: The palatal sinus lifting approach permitted higher postoperative comfort, less postoperative edema, less marginal bone loss around implants, and higher bone density around implants postoperatively.