A ganglion cyst is a soft mass that is surrounded by a dense connective-tissue capsule and is filled with viscous fluid that is rich in hyaluronic acid and other mucopolysaccharides. Ganglion cysts are rarely found around knee, while we experienced 8 patients of various locations around the knee during the period of 1988 to 1990. There were 5 females and 3 males with the average age of 40 years(range 31 years to 49 years). The average follow-up was 16 months (range 12 months to 26 months). Magnetic resonance imaging was performed in three patients to examine the nature of the mass. Two cysts were found communicated with knee joint. In two cases, medial meniscus tear was combined. All the cysts are extirpated completely by extracapsular dissection. Two combined meniscal tears were treated by arthroscopic operation. Histological examination of the resected cysts confirmed the diagnosis of a ganglion. Of the eight patients. one patient showed recurrence 5 months after operation, which required reoperation. Seven patients showed unevenful follow-up without any discomfort or complication.