The case report describes a sinus membrane elevation procedure, where the augmentation was performed exclusively with plasma rich in growth factors (PRGF) and fibrin clot, followed by osseous regeneration at eight months. The patient exhibited a marked osseous atrophy in the premolar-molar area of the left superior alveolar process. Initially, we performed a sinus membrane elevation, with autologous bone on the sinus floor and bovine bone, followed by horizontal augmentation with autologous bone harvested from the mandibular ramus. The fragments were covered with PRGF and fibrin clot. Implants were inserted six months post-intervention, but due to the insertion high speed, a vestibular abscess occurred three months later. The implants and sinus graft were removed; after curettage, the sinus was filled with PRGF and fibrin clot. Eight months later, we observed the bone regeneration and the implants were reinserted. Along with implant insertion, bone was harvested for histological examination. Microscopically, the bone formation was revealed in the sinus, with differences between crestal and apical zones. The bone remodeling process was more advanced in the crestal zone compared with the apical zone. Bone regeneration was complete, and the bone density allowed the implant insertion with appropriate primary stability. Four months after implant insertion, the panoramic radiography and cone-beam computed tomography (CBCT) confirmed the implant osseointegration. Results obtained after using PRGF and fibrin clot alone as osseous addition materials in sinus lifting are highly promising, but in order to draw scientifically reasoned conclusions, further clinical studies are required.