We present a case of oncocytic adrenocortical carcinoma in a 25-year-old man who presented with persistent hypertension, hypokalemia, and a large right adrenal mass. Clinical workup revealed increased serum aldosterone level, suppressed serum ACTH level and high 24-h urine cortisol. Histologically the tumor showed several features of malignancy and electron microscopy confirmed oncocytic differentiation. This case is reported as the first case of an aldosterone and cortisol-producing malignancy with an oncocytic phenotype.