A combined transcranial and transfacial approach has long been the gold standard for surgical management of large tumors with sinonasal and skull base involvement. The extended endoscopic endonasal approach for such pathologies has its advantages, but it has flaws as well, such as anatomic limitations and more ponderous skull base reconstruction and thus higher risk of postoperative complications. Our primary technique for surgical treatment of these pathologies has been a combination of transfacial and minimally invasive transciliary supraorbital keyhole approaches. With the aim to further minimize invasiveness, potential complications, and unsatisfactory aesthetic outcomes during surgical treatment of large tumors invading both the sinonasal area and the skull base, we abandoned the transfacial approach and simultaneously combined the transciliary supraorbital keyhole approach with the endoscopic endonasal approach. The well-known microscope-assisted minimally invasive approach via a transciliary supraorbital keyhole craniotomy was combined with the endoscopic endonasal approach. Six patients with different histologic types of tumors affecting the sinonasal area and the skull base were operated on. The mean operative time was 3 hours, there were no unexpected intraoperative or postoperative complications, and total tumor removal was achieved in each patient. None of the patients experienced complications associated with the surgery during follow-up. Our combined simultaneous multiportal approach enables total tumor eradication with reduced operative time and is associated with minimal intraoperative and postoperative complications, low mortality rate, and excellent cosmetic results.