Thirty four cases of isolated extramedullary relapse after complete remission of acute leukemia were reported. The relapse took place in central nervous system (CNS), genito-urinary system, skin, serous cavity, tonsils, lymph nodes, liver, spleen, gastro-intestinal tract, pancreas and ocular fundus. These 34 cases of isolated extramedullary relapse of leukemia was found in 206 cases with complete remission, constituting 16.5% of the total. In order to discover CNS relapse with no symptoms and signs, the author strongly suggest that cerebrospinal fluid examination be carried out periodically. If some symptoms signs in the patient can not explained by infection, congestion or other causes, extramedullary relapse should be considered and further examination and appropriate treatment are needed.