Myxedema coma is a rare complication of hypothyroidism. Clinical examination may reveal hypotension, bradycardia, and hypothermia. Laboratory tests may show hyponatremia, lipid disorders, and elevations of creatine kinase, liver, and cardiac enzymes. We describe four cases diagnosed in our hospital during the period 1999-2017. The patients were related to amiodarone treatment, noncompliance with hormone replacement therapy, or a new diagnosis of hypothyroidism. Intravenous hormone replacement therapy was effective in three of the cases and one died. The outcome of this disease may be fatal as seen in one of our cases.