In this report, a case of a Nasopharyngeal Carcinoma invading head of mandibular condyle and the Temporomandibular Joint (TMJ) in a 17 year old male has been presented. He had rapid weight loss with TMJ complaints without any previous trauma history. A detailed evaluation with magnetic resonance imaging showed parapharyngeal mass invading the right TMJ and its extension to the right anterior pontocerebellar region. Pathological examination of the biopsy of the mass showed a type II Nasopharyngeal Carcinoma (NPC). An expeditious weight loss with trismus may indicate a possible malign neoplasm such as NPC.