Purpose: Sinus floor augmentation has become a routine procedure with predictable results. Flapless implant placement is recommended for a series of indications with sufficient bone volume. Flapless surgery in the atrophic maxilla is presented as a refinement of the endoscopic subantroscopic latero-basal sinus floor augmentation (SALSA) technique. Materials and Methods: Based on computerized tomography (CT) scans, the site of sinus trephination and implant positions are planned using a commercially available planning program, and surgical templates are fabricated according to the data of the treatment plan. Subantral space is augmented using the SALSA technique without raising a mucoperiosteal flap. Implants are placed transgingivally without raising a mucoperiosteal flap, with endoscopic control of the cover screw at the bone level. Results: In a case series of 6 patients, 21 implants were placed and augmented simultaneously. The mean augmentation height was 10.7 mm (range, 5.7 to 16.6 mm); the mean residual bone height was 5.1 mm (range, 1.9 to 12.1 mm). Complications such as insufficient primary stability and sinus membrane perforation were treated without changing to an open surgical approach. Discussion and Conclusion: Flapless sinus augmentation (FSA) can reduce the surgical trauma significantly. The procedure has high acceptance by the patient and less postoperative discomfort. FSA enlarges the spectrum of minimally invasive surgery and may offer better vascularization and less alveolar resorption. Keywords: endoscopy, minimally invasive surgery, sinus augmentation, 3-dimensional surgical templates