Beckwith-Wiedemann syndrome presents with multisystemic patterns of congenital anomalies and macrosomia. This syndrome was independently described by Beckwith in 1963 and by Wiedemann in 1964. There is wide spectrum of clinical manifestations, including prenatal or postnatal overgrowth, neonatal hypoglycemia, macroglossia, visceromegaly, omphalocele, hemihypertrophy and a predisposition for embryonal tumors, most frequently Wilms' tumor. We managed a case of Beckwith-Wiedemann syndrome with left adrenal cortical neoplasm of undetermined malignancy.