Liver cysts are a very common type of liver disease. I am often asked in the clinic by patients with physical examination reports what kind of disease liver cysts are and whether they need surgery. Here I will explain for this disease with clinical examples. Simple hepatic cyst is one of the most common types of non-parasitic cysts in the liver. Its cause is generally considered to be a stagnant cyst formed after blockage of tiny bile ducts, usually small in diameter, the number can be more than one, slow growing, with smooth walls and clear cystic fluid, without obvious symptoms and without special treatment. Liver cysts can sometimes grow huge, and I once dealt with a patient who was found by chance during a gynecological surgery and the cyst even grew into the pelvic cavity. Such huge liver cysts mostly have obvious compression symptoms, such as nausea, bloating, vomiting, abdominal pain and other clinical manifestations, and usually require surgical management. However, there is a genetic disease called polycystic liver, often combined with polycystic kidney, and because the cysts are extensive and multiple and the liver is not functional, such patients are not suitable for general surgical treatment and often need liver and kidney transplantation in advanced stages. Special attention should be paid to differentiate polycystic liver cysts from cystadenoma and cystadenocarcinoma of the liver. The latter two are true tumors that require complete surgical resection, and cystotomy does not solve the problem, but can have catastrophic consequences. The main points of differentiation are whether the morphology of the cyst is rounded, whether the cyst wall is smooth, and whether there are soft tissue shadows in the cyst wall, which can be better identified by plain and enhanced dual-phase CT. As already mentioned, asymptomatic simple hepatic cysts do not require special treatment, but larger cysts, cysts combined with infection and bleeding, cysts with obvious pressure symptoms or cystadenoma/carcinoma cannot be ruled out, need to be treated. The treatment options are minimally invasive intracystic percutaneous alcohol injection, laparoscopic cyst windowing, open cyst windowing and partial hepatectomy, etc. The most appropriate treatment needs to be chosen on a case-by-case basis. My management principle is: alcohol injection or laparoscopic windowing can be tried for single predominantly hepatic cysts, but surgical treatment is often more thorough for multiple huge hepatic cysts.