Metastasis from the prostate gland to the mandible is rarely encountered and commonly present with non-specific features like unexplained pain, swelling, and numb chin syndrome. Here we present a case with metastatic prostate adenocarcinoma detected secondary to oral manifestations. Patients present with unexplained facial pain and numbness should alert clinicians to the presence of malignant disease, and appropriate hematological, radiological and or histological investigations should be performed. Thereby, clinicians can prevent the overlook of the first signs of metastasis, accelerate the early diagnosis and positively orientate the prognosis of the disease, especially in a patient without known malignancy.