Malignant peripheral nerve sheath tumor (MPNST) is a rare soft tissue malignancy usually found in patients with neurofibromatosis type 1 (NF1) with a poor outcome. Although MPNST can be found in any part of the body including head and neck or extremities, intrathoracic MPNST with or without NF1 is uncommon, especially in children or adolescents. Reported herein is a case of huge intrathoracic MPNST in a 16-year-old girl with NF1, and a brief review of the literature.