Objective: This study was designed to evaluate the efficacy of the Direct Implant Valve Approach (DIVA) versus the transcrestal approach assisted with a balloon for the rehabilitation of posterior atrophic posterior maxilla with implant-supported fixed prostheses. Patients and methods: This prospective clinical study included 14 patients (7 males and7 females). They ranged from 29 to 69 years with the posterior atrophic edentulous maxilla. All patients underwent clinical and radiographic examinations, including full-mouth intra-oral photographic series and cone-beam computed tomography (CBCT), which were performed to assess the maxillary sinus floor. The predictor variables were intraoperative primary stability and level of sinus membrane lifting. The outcome variables were secondary implant stability (Osseointegration) and the level of bone height gained. Results: The mean bone height before surgery was 5.814± 0.669mm, 6.84± 0.861mm. for DIVA and Balloon groups respectively which became 12.78± 0.526 and 10.81 0.671after 6 months postoperatively. ISQ was 39.00±2.160, 40.00±2.160 which became 71.71±1.604, 70.43±1.272 after 6months for DIVA and Balloon groups respectively. Conclusion: The Balloon approach was an effective approach to augment alveolar bone height without causing maxillary sinus membrane perforation. However, the DIVA approach was used in the limited residual alveolar bone height and required meticulous surgical procedures.