Pancreatic mature cystic teratomas are very rare with limited cases found in the literature. These lesions raise a diagnostic challenge and complicate the surgical approach not only because of their anatomic position but also because of their ever-growing size. An elusive diagnosis, usually leads to the operative theatre where surgical resection takes place. We present a rare case of a large pancreatic cystic teratoma extending into the mediastinum in a 29-year-old woman which was succesfully managed with en-bloc distal pancreatectomy and spleenectomy.