We report on a case of closed chest trauma with an unusual latent period of 11 weeks in a woman 26 years old. The patient had a dual thoracic duct with a dual lesion and was evaluated using lymphography and CT. We discuss the pathogenetic mechanism and the unusual radiological appearance with discontinuity of the duct, and an increase in back pressure which promotes dilatation of lymphatic vessels and nodes. The dual duct had two separate traumatic consequences: a chyloma on the right and leakage in the pleura on the left. Pleuroperitoneal shunting was effective after failure of conservative treatment. Two years after discharge the patient is asymptomatic with normal chest X-ray image. She is near term in a normal pregnancy and without signs of silent malignancy.