Dental implant placement associated with augmentation of the sinus floor in the severely atrophic maxilla can be performed in 1- or 2-surgical stages, depending on the height of the residual alveolar bone. A minimum of 4 to 5 mm of residual alveolar bone height is recommended for a 1-stage surgical procedure. The present study describes a 1-stage procedure in cases where the residual alveolar bone height in the posterior maxilla was 1 to 2 mm. A total of 55 hydroxyapatite-coated dental implants were inserted in 20 grafted sinuses of 20 patients. No case presented any difficulty in achieving initial stabilization and parallelism. No perforation of the sinus membrane or clinical complications of the sinuses were evident. Prior to exposure, radiographic evaluation revealed bone consolidation and a close bone-implant relation. At second-stage surgery, there was no clinical evidence of crestal bone loss around the implants. All implants were clinically osseointegrated. All patients received fixed implant-supported prosthesis. The mean follow-up was 26.4 months (range 15 to 39 months). There was no implant loss after loading. The following surgical modifications are essential: a wide lateral window opening, the use of a bone mill to homogenize the bone graft, meticulous condensation, and clinical measurements to ensure implant parallelism.