A double mitral valve is one of the rarest of congenital anomalies of the heart. Only 17 instances have been reported. Herein we report the 18th case and the only one in which cardiac catheterization and angiocardiography were performed. Report of Case A 55-year-old bartender who drank whiskey freely was first admitted into the Episcopal Hospital on June 3, 1954, for treatment of a fractured mandible sustained during a fist fight while intoxicated. He was told at the age of 14 years that he had a heart murmur. At the age of 51 he was told that he had hypertension. Since that time he had been conscious of slight shortness of breath after climbing three flights of steps but only when under the influence of liquor. Physical examination revealed a well-developed man except for possibly disproportionately thin lower extremities. The blood pressure in the right arm was 204/110 mm. of