Running title: A plunging ranula extended into parapharyngeal space Ranulas are lesion of sublingual gland origin, which occur in the floor of the mouth. Most ranulas, whether simple or plunging, are pseudocysts without and epithelial lining and ranulas have higher levels of salivary amylase and protein content. They can be classified into two types based on their extent: simple ranulas, confined to the sublingual space and plunging ranula which extend into adjacent spaces. Plunging ranula requires differential diagnosis with other lesions (neuroma, monomorphic adenoma, hemangioma, lipoma, dermoid cyst, lateral cervical cyst). The patient was diagnosed as plunging ranula. We experienced 17 years old male, visited to our department, who complain Rt. cervical swelling and in MRI view, this lesion involved sublingual, submadibular, parapharyngeal, skull base. We experienced a rare case of plunging ranula, extended into parapharyngeal space. We report the case.