The association of a thyroid storm and diabetes ketoacidosis is relatively rare. We report two cases.The first one is a 20 years old woman, with no history of diabetes, who came with ketoacidosis, a history of non-medicated thyrotoxicosis, and she was complaining about fever, a thyrotoxicosis syndrome, a vascular goiter, and exophthalmos. Her general condition had improved significantly after the treatment in emergency and under maintenance therapy.The second one is a 54 years old female, with a case of diabetes mellitus, who presented a ketoacidosis. But despite the control of the situation, the patient’s consciousness level became disturbed and she presented hyperthermia. The thyroid function tests revealed hyperthyroidism. Thus, thyroid storm was evocated and managed. The patient finally passed away despite the prompt medical care. In these two cases, a thyroid storm, associated with Graves’ disease covered by diabetic ketoacidosis was the final diagnostic.Thereby, for patients having diabetic ketoacidosis we should seek an eventual thyroid storm, and vice versa: in fact, there are some symptoms in common. But there are scores to help systematize the diagnosis. The management is acutely controlled based on antithyroid drugs in high doses, betablockers and corticosteroids. We should not disregard the search for and treatment of precipitating factors: ketoacidosis in our cases. And identify the thyroid underlying disease: most commonly Graves' disease