A study performed at the Internal Medicine Emergency Department of the General Hospital "La Paz" (Madrid) over a six month period is presented. Its goal was to check the problems of the diabetic patient at his entrance to the medical emergency. We review the emergency pathological causes and we established that vascular (32%) and acute metabolic (17%) alterations were the most common pathologies, both in insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetic patients. We analyzed the acute metabolic alterations considering that they can be foreseeable with an adequate knowledge of the disease. We point out an aspect that to our knowledge is basic: the diabetological information-education of diabetic patients (only 5% had a good knowledge of the disease and, furthermore, only 18% declared to have received some diabetological information). We also highlight the overuse that diabetic patients do of the hospital emergency departments, as a consequence of the previously mentioned poor information received which also reflects the insufficient or inadequate medical assistance in Primary Care Centers.