Stafne bone cavity (SBC) is an uncommon lesion of the mandible; and generally found incidentally on routine radiographic examinations. The radiographic differential diagnosis of SBC includes a variety of lesions including odontogenic cysts, benign tumors, or bone metastases. In the present case, a 22-year female patient was admitted with chief complaint of pain in the right mandibular molar area. On panoramic radiographic examination, a non-specific large radiolucent lesion related to mandibular molar teeth was detected and extra-oral surgical intervention was planned. However, on examination with cone-beam CT(CBCT), a SBC was suspected due to lack of lingual cortical plate; and intraoral surgical exploration confirmed the diagnosis showing a cavity with small inflamed salivary gland tissue. Examination with CBCTon suspicious jaw lesions helps avoid unnecessary extraoral surgical interventions.