A case of mesenteric Castleman's disease of plasma cell type is represented here with CT and ultrasonographicfindings in a 54-year-old man. Only less than 20 ases of mesenteric origin were reported worldwidely. Welldefined, homogenous soft tissue mass with pin-point calcification and multiple, small adjacent nodules in the freely movable mesentery anre highly suggestive of Castleman's disease in CT. Ultrasonography showed homogenous,hypoechoic mass with acoustic enhancement in the lower abdomen changing in location according to positional change. In the differential diagnosis of round, well defined soft tissue mass, which appeares in the vicinity oflymphoid tissue, Castleman disease must be considered.