Congenital mesoblastic nephroma is a rare renal tumor of early infancy with a favorable outcome after complete surgical removal. It consists of a heterogeneous group of spindle cell tumors. Early and accurate prenatal diagnosis of the renal tumor may improve the outcome of affected pregnancies by implementing the best strategy for prenatal management and delivery. But detection of congenital mesoblastic nephroma in a fetus is rare. To the authors' knowledge, there are fewer than 30 reports of a prenatal diagnosis of a mesoblastic nephroma in the literature. This case describes the prenatal sonographic diagnosis of cellular congenital mesoblastic nephroma.