Primary undifferentiated sarcomas (also called embryonal sarcomas or malignant mesenchymomas) are an exceptional form of cancer of the liver, occurring preferentially in children or adolescents. They can exhibit poor differentiation, embryonal rhabdomyosarcoma being the most frequent. To date, therapeutic success has been reported only rarely. The authors describe the case of a 16 year old boy with primary hepatic sarcoma showing a rhabdomyoblastic differentiation, who is in complete remission two years after total surgical resection and polychemotherapy.