The evolution of endoscopic sinus surgery has led to a paradigm shift in the management of sinonasal and anterior skull base tumors in the past decade. Endoscopic resection is considered by many institutions to be the gold standard approach even for extensive pathology. Endoscopic tumor surgery should not imply less surgery but rather an alternative to external operations providing the same access and enabling equivalent or superior visualization for resection of tumors. It also avoids much of the potentially significant morbidity associated with external operations. Successful endoscopic tumor resection requires experience, an understanding of tumor behavior, and the development of a unique skill set. Tumor removal is often performed inside-out. Regions such as the anterolateral maxilla and frontal sinus require special access. Orientation of the surgeon is different to that of simple inflammatory disease. A structured approach to vascular control is important to ensure a workable surgical field. The final cavity and reconstruction need to be fashioned to ensure that reasonable sinonasal physiology and function are retained, including the lacrimal apparatus. The endoscopic cavity created after extensive surgery requires different care compared with the mucosal-preserving techniques of inflammatory disease. This article describes these key methodological differences that enable extended endoscopic surgery of the sinonasal tract and anterior skull base.