PURPOSE: The purpose of this study was to analyze the CT findings of hepatoblastoma before and afterchemotherapy, and to compare them with surgical and pathologic features. MATERIALS AND METHODS: Twelvehepatoblastoma patients underwent chemotherapy prior to surgery; in all cases, CT scanning was performed beforeand after chemotherapy. We reviewed the findings with special attention to changes in tumor volume, the extent andpattern of contrast enhancement, the extent of low-attenuation area in the tumor, the presence of a septum, andcalcification or ossification within the mass before and after chemotherapy. Post-chemotherapy CT findings werecompared with operative and pathologic findings. RESULTS: After chemotherapy, the volume of the tumor massdecreased in all patients, and the extent of involved segments decreased in nine(75%), the non-enhancing areawithin the mass, on the other hand, increased in nine (75%). On pre-chemotherapy CT, calcifications were detectedin seven patients(58%), and on post-chemotherapy CT, in nine (75%); the extent of calcification increased in sevenpatients. On the basis of CT findings, viable tumor and necrosis areas could not be distinguished. Massivecalcification or an osteoid mixed with loose connective tissue was noted in the mesenchymal component of thetumor; the whirling pattern of enhancement within the area of low density asen on CT scanning corresponded toosteoid mixed with loose connective tissue, which contained rich blood vessels. CONCLUSION: We describe the CTfindings of hepatoblastoma both before and after chemotherapy, highlighting the changes which occurred. Anunderstanding of these changes is helpful for the proper management of this condition.