A case of renal pseudotumor in a 47-year old female is reported. She was admitted with the complaint of right flank pain. Intravenous pyelography showed filling defect in right renal pelvis and spreading deformity of calices with compression of infundibuli. Ultrasonography and computed tomography demonstrated round renal mass. Since possibility of hypovascular tumor was not completely ruled out by right selective renal angiography, subsequently performed, then right nephrectomy was done. Bisected specimen revealed mal position of renal lobe (lobar dysmorphism). Microscopic appearance showed normal renal parenchyma. The literature is also reviewed.