Small bilateral renal cysts are cystic diseases of both kidneys, the cysts are small and most of the patients are asymptomatic. The causes of renal cysts include primary lymphedema and secondary lymphedema, which can be unilateral or bilateral at the same time, and the size of the cysts varies from a few millimeters to more than ten centimeters. In general, small cysts in both kidneys may not have any clinical symptoms and do not affect renal function. Patients do not have abdominal pain, abdominal distension, hematuria, proteinuria and so on. Most patients are found by chance during urinary ultrasound and CT examination. If the cyst is large, an abdominal mass can be found during the examination, which can also cause abdominal pain, abdominal distension, lumbago and other symptoms. Urologic ultrasound is the preferred examination method for checking renal cysts. Typical ultrasound manifestation is smooth wall of the cyst with clear boundary. If secondary infection is present, there may be fine echogenic areas. If the renal cyst is less than 5 cm, the patient is asymptomatic and can be observed dynamically. If the renal cyst is larger than 5 cm, it may cause abdominal pain, hematuria, and may also affect renal function, and surgical treatment, such as renal cyst decortication, needs to be chosen. In daily life, we should pay attention to nutritional balance, proper water intake, less fried food and so on.