Patients suffering from polycystic liver disease may develop Hepatic Venous Outflow Obstruction, Portal Vein Obstruction and/or Inferior Caval Vein Syndrome because of cystic mass effect. This can cause portal hypertension, leading to ascites, variceal haemorrhage or splenomegaly. For this review, we evaluate the evidence to provide clinical guidance for physicians faced with this complication. Diagnosis is made with imaging such as ultrasound, computed tomography or magnetic resonance imaging. Therapy includes conventional therapy with diuretics and paracentesis, and medical therapy using somatostatin analogues. Based on disease phenotype various (non-)surgical liver-volume reducing therapies, hepatic or portal venous stenting, transjugular intrahepatic portosystemic shunts and liver transplantation may be considered. Because of complicated anatomy, use of high-risk interventions and lack of empirical evidence, patients should be treated in expert centres.