The occurrence of leiomyosarcoma was demonstrated in a tissue cylinder obtained by liver biopsy in a 68-year-old woman with unclear hepatomegaly. The patient died 8 months after she had experienced first signs of illness. Autopsy revealed a primary leiomyosarcoma of the liver with metastases in the lungs, bilaterally in the pleura, in the kidneys, and in the periportal and spleno-pancreatic lymph nodes. The occurrence of a primary tumour in the urogenital system or in the gastrointestinal-tract could be excluded. The diagnosis of leiomyosarcoma was based on the microscopical demonstration of smooth muscle fibres with enlarged red-like and partially atypical cell nuclei and atypical mitoses. Furthermore, we observed extensive necroses and haemorrhagia in the tumour tissue. Preexisting tumours of the liver as, e.g., teratoma or hepatoblastoma were not found. No cirrhosis of the liver could be detected. Obviously, the leiomyosarcoma had its origin in the smooth muscle fibres of the liver vascular system.--According to the literature primary leiomyosarcomas in the liver are only rarely found.