Nonketotic hyperosmolar coma (NHC) is characterized by severe hyperglycemia; absence of, or only slight ketosis; nonketotic acidosis; severe dehydration; depressed sensorium or frank coma; and various neurologic signs. This condition is uncommon in type 1 diabetes. Because of little or no osmotic diuresis in patients with diabetic nephropathy, increases in plasma osmolality and therefore the likelihood of neurologic symptoms are limited. A 20-year-old male patient with type 1 diabetes with chronic kidney disease on conservative treatment (glomerular filtration rate [GFR], 18 mL/dk) presented with acute nonketotic hyperosmolar syndrome. The patient was admitted presenting with thirst, fatigue, and drowsiness. Blood biochemistry levels were urea 87 mg/dL, creatinine 5.09 mg/dL, glucose 830 mg/dL, glycosylated hemoglobin (HbA1c) 8%, C peptide <0.3 ng/mL, sodium 131 mmol/L, chloride 93 mmol/L, potassium 5.2 mmol/L, and calculated serum osmolality 385 mOsm/kg. The presumptive diagnosis on admission was nonketotic hyperosmolar syndrome precipitated by urinary infection. This is the first case report of hyperosmolar coma in a patient with type 1 diabetes with chronic kidney disease.