Congenital mesoblastic nephroma(CMN) is a rare kidney tumor usually diagnosed at birth or within the first 3 months of life as unencapsulted and locally invasive fibrous lesion. CMN is an infantile spindle cell tumor of the kidney that is subdivided into classical or atypical(cellular) form based on the degrees of cellularity and mitotic activity. CMN is associated with a good prognosis and in most cases, surgery alone may be curative. We report a case of CMN detected by prenatal ultrasonography in premature infant.