Carcinosarcoma of the adrenal gland is an extremely rare variant of adrenocortical carcinoma, characterized by a biphasic pattern of carcinoma and sarcoma-like components. We report a case of adrenal carcinosarcoma occurring in a 61-year-old Korean man who presented with right flank pain of one month duration radiating to the back and right iliac crest. The tumor measured 12 x 12 x 7 cm and adhered to the liver and right upper pole of the kidney. The carcinomatous component of the tumor showed polygonal cells in a broad anastomosing trabecular pattern with delicate slit-like vascular channels; the sarcomatous component showed uniform spindled cells in a fascicular pattern. Both the carcinomatous and sarcomatous portions of the tumor were positive for pan-cytokeratin, and vimentin stained only the sarcomatous areas.