Over the past couple of decades, endoscopic skull base surgery (ESBS) has significantly evolved and is applied to a broad range of skull base pathologies, including sinonasal malignancies. Recent studies have demonstrated remarkable progress of ESBS in complete resection with low morbidity and extension of its application to larger and more complex lesions. In this review, we focus on the evolution of functional preservation and multiportal approaches. Progress in preoperative assessments and surgical techniques improved the preservation of olfactory function after ESBS. The technical feasibility of olfaction preservation even after resection of olfactory groove lesions has been reported. To overcome the limitations of extending use of the endoscopic endonasal approach in surgical fields, various types of multiportal approaches, including combinations of the endoscopic endonasal and transorbital, transmaxillary, or transoral approach, have been reported, as they are useful for complete resection of extensive pathologies while limiting morbidity. These innovative techniques are still in the process of maturation. Hence, an ongoing critical evaluation is essential to ensure efficacy.