INTRODUCTION:The introduction of computer guided surgery in implant dentistry has marked a new era allowing various procedures to be performed with a great level of precision and accuracy. Recently, a novel design of the lateral window osteotomy, the "Low Window" sinus lift technique, was proposed to facilitate sinus augmentation and reduce postsurgical patient discomfort. AIM OF THE STUDY:The aim of this study was to evaluate the safety and effectiveness of the "Low Window" lateral sinus lifting technique. MATERIALS AND METHODS:The study group included 12 patients that were treated using the low window lateral sinus lift technique with simultaneous implant placement. This was facilitated using a Three dimensional (3D) printed surgical guide. Assessment on postoperative pain, edema, implant stability, vertical bone height gain, and complications such as Schneiderian membrane perforation. RESULTS: All patients experienced mild pain postoperatively with a significant decrease in pain from the 1st to 3rd day. Sinus membrane perforation occurred in 2 patients as well as mild postoperative bleeding on the first day. A statistically significant increase in vertical bone height (p<0.001) was observed as well as in implant stability, while marginal bone loss was within normal limits. CONCLUSION: The use of computer guided low window lateral sinus lift technique resulted in a satisfactory outcome in terms of postoperative pain, edema, bleeding, sinus perforation rates, implant stability, vertical bone height gained and marginal bone loss.