his case report represents some ultrasonographic features of the liver and brain in a patient with congenital leukemia. A 22-day-old male infant was admitted to Jichi Medical School Hospital because of systemic multiple bluish-skin nodules. Physical examination revealed marked hepatosplenomegaly. Bone marrow aspiration revealed acute lymphoblastic leukemia. Ultrasonography showed multiple hypoechoic areas surrounding the intrahepatic portal branches. On the other hand, no abnormalities were detected in two-dimensional echoencephalography. Clinical remission was achieved 33 days after the start of antineoplastic chemotherapy. Simultaneously the size and ultrasonographic pattern of the liver became normal. A few days after the onset of remission, however, CNS involvement was found. Echoencephalography revealed a slight enlargement of the anterior horn of the lateral ventricles. This tendency was noted in the third ventricle 2 months later, and became pronounced several days before the patient's death (i.e., 6 months after admission). This was a rare case in which hepatic involvement and progressive enlargement of brain ventricles in congenital leukemia could be ultrasonographically detected and followed up.