We report the case of a premature female newborn of the 35th gestational week with a congenital mesoblastic nephroma. The tumor was prenatally diagnosed in the 32nd week of gestation. By close sonographic controls, rapid enlargement was verified towards the end of the 35th week of gestation. This was probably caused by hemorrhage into the tumor. Anemia and postnatal disseminated intravascular coagulation followed. Cesarean section was done, because the anemia was suspected by Doppler sonographic evaluation. Disseminated intravascular coagulation could not be sufficiently controlled by conservative means but only by surgical removal of the tumor. The tumor turned out to be a congenital mesoblastic nephroma by histologic evaluation. Despite postoperative anuria and catecholamine dependency, our patient eventually showed a very favourable outcome. Diagnosis, clinical behavior and therapy of this tumor with a generally good prognosis are described and discussed.