Presenting one case of nephroblastomatosis (NB) the diagnostic approach by different imaging modalities is discussed. Ultrasound (US) of the kidneys as a basic examination showed one focus of NB but missed two further foci which were clearly shown by contrast enhanced CT and MR. Contrast enhanced CT has been considered to be the most sensitive method in primary diagnosis of NB and follow up. However, in our case contrast enhanced MR examinations showed the foci of NB more clearly than CT. Since the false negative rate of MR is not yet known, we recommend the use of a contrast enhanced MR study parallel to a basic CT examination. If MR findings are consistent with CT findings, no further CT examinations are necessary for follow-up. Since US can miss a considerable amount of foci of NB, basic evaluation of NB and associated lesions by US alone should be avoided.