Hereditary haemorrhagic telangiectasia is a genetic disease characterised by the presence of teleangiectases virtually involving every organ. Hepatic involvement is represented by a spectrum of vascular abnormalities, which evolve in a continuum from tiny teleangiectases to substantial vascular malformations, potentially with a progressively greater arteriovenous shunt. Liver involvement in hereditary haemorrhagic telangiectasia is almost always asymptomatic; on the other hand, hepatic vascular malformations can induce severe complications, depending on the predominant venous side of the arteriovenous fistulas-high-output cardiac failure in the case of hepatohepatic fistulas, and portal hypertension in the case of hepatoportal fistulas. Doppler sonography can detect and stage hepatic vascular malformations in subjects with hereditary haemorrhagic telangiectasia; according to Doppler sonographic grading, appropriate advice for follow-up and/or therapy can be given.