Sinus lift is a widely described procedure that allows to insert dental implants in the posterior atrophic maxilla to obtain a prosthetic rehabilitation. When pristine bone is below 4mm in height many authors suggest a two step procedures, performing a sinus lift at a first surgery, followed by implant placement after 4-6 months of healing, This is due to the low primary stability that an implant could have when inserted in such a thin bone. When preexisting bone is more than 4-5mm a single step procedure is preferred with sinus lift and implant placement performed during the same surgery. This will allow a shorter clinical time. In the reported case bone height at tooth number 5 was 6 mm in height, but at site number 3 was only 2.5mm. Relying on the high primary stability of AoN Implants IS-FOUR® implants, a single step sinus lift was chosen (sinus lift and implant placement at the same time), with a two-stage implant positioning. After four months of healing abutment connection was performed and a digital impression with an intra oral scanner was taken. A full zirconia bridge was delivered on implants in position 3 and 5.