Ultrasonography is known to be a good method of determining the stage and changes after chemotherapy of neuroblastoma. We analyzed changes of sonographic findings in relation to the ratio of vany1 mandelic acid/creatinine (VMA/Cr) in 16 proven cases of adrenal neuroblastoma following chemotherapy. There was a positive correlation between the change of size of the VMA/Cr. However, there were some limitations concerning the detection of tumor recurrence.