A pheochromocytoma is an uncommon tumor that originates from the chromaffin cells of the adrenal medulla. Also, adrenal tissue not located in its typical position is referred to as ectopic adrenal tissue. It is relatively uncommon in adults and is usually asymptomatic. Therefore, a pheochromocytoma arising from ectopic adrenal tissue is even a rarer finding and presents as a unique diagnostic challenge. A 20-year-old man presented with vague abdominal pain, and upon imaging, a mass located behind the liver was initially discovered. Subsequently, it was identified as a mass growing in an ectopic adrenal gland. He underwent exploratory laparotomy and resection of the mass. A pheochromocytoma in an ectopic adrenal gland was confirmed by histopathology.