Black adenoma is known to be a rare variant of adrenal cortical adenoma containing characteristic abundant lipofuscin pigments in the cytoplasm. Almost all of them are nonfunctioning and only occasionally they are associated with Cushing's syndrome or primary hyperaldosteronism. We present two cases of black cortical adenoma of the adrenal gland associated with Cushing's syndrome in a 24-year-old woman and a 64-year-old man. This report dealt with clinical and pathologic presentation including ultrastructural identification of lipofuscin pigment.