Biopsy of lesions in the peripharyngeal and skull base regions frequently is difficult with standard computed tomography-guided retromandibular and retromaxillary approaches. An alternative approach via the mandibular sigmoid notch (concave superior margin of the mandibular ramus) was used in 13 patients. It provided easy access to deep lesions and to areas such as the skull base and clivus, which are unapproachable with other methods.