Non cardiogenic pulmonary oedema occurs rarely in patients with diabetic ketoacidosis, except in conjunction with an infection. A case is reported of non cardiogenic pulmonary oedema in a patient with severe diabetic ketoacidosis, which resolved within 72 h with oxygen supply only. There were no objective facts which could explain its pathogenesis, despite the important pulmonary asymmetry due to a unilateral diaphragmatic paralysis.