Skull base surgical defects present unique challenges to anatomic and functional reconstruction. Fortunately, many endonasal skull base defects are successfully managed with a variety of local and regional reconstructive techniques. However, when prior surgery or radiotherapy eliminates the use of these local and regional reconstructive options, more elaborate free tissue transfer techniques are required. Managing endoscopic skull base defects of the anterior cranial fossa and clivus is further complicated by the limited access afforded for flap inset. The following case report describes durable reconstruction of a clival defect with an endoscopically-tunneled adipofascial radial forearm tissue transfer. The case highlights importance of a multidisciplinary surgical team approach with strong foundations in endonasal skull base and reconstructive surgery to achieve successful reconstruction of complex endonasal defects.