The discovery of an haemolytic anemia after a diabetic ketoacidosis led us to diagnose glucose-6-phosphate dehydrogenase (G6PD) deficiency in a 38-year old male patient. After a favorable course, we reviewed the links between this genetically transmitted enzymatic defect and diabetes mellitus, a public health concern in La Réunion. This description is a rare case of G6PD deficiency revealed after diabetic ketoacidosis in an adult.