With the exception of cavernous haemangioma, mesenchymal tumours are rare. They may affect children and adults, and many are very similar histologically to their extrahepatic counterparts. They may be associated with other congenital abnormalities in children or other conditions (e.g., Epstein-Barr virus [EBV], HIV infections) but they usually do not occur in the context of chronic liver disease. They are divided in this chapter into benign mesenchymal tumours, malignant mesenchymal tumours, and haematolymphoid malignancies.