Systemic lymphangiomatosis is a rare disease characterized by the exageration of lymphatic channel proliferation, occurring in children and young adults. We describe an extremely rare case of congenital systemic lymphangiomatosis in a newborn who had ascitis and respiratory failure develop immediately after delivery. Death occurred during the first hour of life. Autopsy findings showed numerous cysts in soft tissues of the cervical area, mediastinum and diaphragm, and several other organs including the liver, spleen, thyroid and kidneys. The severe and diffuse involvement with cysts in both lungs by lymphangiomatosis was associated with poor prognosis and death in our case.