Pulmonary mucoepidermoid carcinoma (PMEC) is an extremely rare salivary gland-type tumor that arises from submucosal bronchial glands and accounts for less than 1% of lung tumors. Here we describe a very unusual case of high-grade PMEC in a 17-year-old male, in whom low-grade tumors are more common. The clinical course was characterized by extensive mediastinal involvement, ipsilateral hilar lymph node metastasis with extranodal extension, and bronchial margins involved with disease. PET-CT and FNAC was done as part of the diagnostic process followed by chemotherapy, surgical debulking, and left pneumonectomy. Pathology confirmed high-grade tumor with multiple adverse prognostic features. This case demonstrates how difficult it is to diagnose PMEC in adolescents and that even if diagnosed early, high-grade PMEC can have aggressive biological behavior requiring tailored management approaches involving multidisciplinary teams.