An enlarged Column of Bertin is a frequent cause of renal pseudotumor. In a retrospective study of the ultrasound findings in 11 patients with columnar hypertrophy, we have attempted to establish objective sonographic criteria of this entity. Columnar hypertrophy appears as a renal mass with the following characteristics: (1) indents the renal sinus laterally; (2) clearly defined from the renal sinus; (3) largest dimension of less than 3 cm; (4) continuous or contiguous with the renal cortex; and (5) Echogenicity close to that of the cortex. Two minor criteria are also presented, and the present appropriate use of the criteria is suggested.