Symptoms in polycystic liver disease are due to both the number and size of cysts; treatment is usually directed at the largest cyst. Simple percutaneous cyst aspiration is associated with a high recurrence rate. Alcohol sclerotherapy, laproscpic cyst deroofing and liver resection have been used to treat cysts ranging from 5-20 cm. We report the successful treatment of symptomatic giant liver cyst with alcohol sclerotherapy. A 44 year old otherwise healthy female was evaluated for a 2-day history of worsening epigastric abdominal pain and fullness. Laboratory investigations revealed normal liver enzymes and function and mild normocytic anemia. Abdominal ultrasound (US) and computed tomography (CT) scan showed multiple hepatic cysts with a dominant cyst measuring 27 cm in diameter. The dominant cyst was treated by a CT-guided percutaneous drainage followed by alcohol sclerotherapy. A total of 5.3 liters of dark brown fluid was aspirated and 50 ml of 98 % absolute alcohol was injected as sclerosing agent. Cystic fluid analysis was unremarkable and consistent with the diagnosis of polycystic liver disease. Abdominal pain and fullness immediately and completely resolved. The procedure was well tolerated without immediate complications. The liver enzymes remained stable within normal range along with synthetic function of the liver. To our knowledge this is the largest reported liver cyst that was safely and successfully treated with CT-guided percutaneous aspiration and alcohol sclerotherapy. This procedure should be considered before exploring more invasive and costly treatment options.