[en] CT whole-body scanning has been performed in 20 children in the evaluation of a suspected Wilms's tumour. All the patients had abnormal urographic findings including a non-functioning kidney in 6 cases, severe urographic changes in ten cases and minor alterations suggesting a small spaceoccupying lesion in four patients. A solid tumour was found in 13 of the patients, eight were renal tumours and five neuroblastomas. The rest of the children had benign lesions as the underlying cause of the abnormal clinical and radiological findings. CT was superior to IVU in the differentiation between a solid tumour and benign lesions such as cysts and hydronephrosis; the examination gave important supplementary information of the size and extent of the solid nature of tumours and tended to be helpful in the preoperative differentiation between Wilms' tumor and neuroblastoma. (orig.)