Malignant rhabdoid tumor of the liver. A distinct clinicopathologic entity. A malignant rhabdoid tumor occurring as a primary hepatic neoplasm in a six-month-old white infant is reported. It was treated by an attempt at total resection involving right hepatic lobectomy and by chemotherapy with cis-platinum, VP-16, and Adriamycin. Despite this, recurrence of the tumor resulted in the girl's death within three months. The neoplasm showed typical light microscopic features of malignant rhabdoid tumor as well as filamentous cytoplasmic inclusions by electron microscopic examination and staining for both cytokeratin and vimentin by immunohistochemistry. The classic clinicopathologic features of this tumor support the concept that malignant rhabdoid tumors similar to those of the kidney may occur in extrarenal sites. 