Ganglion is a common clinical entity, usually superficial in location, therefore easily diagnosed and most common tumors of the hand which represent 50 to 70% of all soft tissue tumors of the hand. The soft mucin filled cyst is attached to the adjacent underlying joint capsule, tendon, or tendon sheath. The most common ganglion is the ganglion on the dorsal side of wrist, with its origin at the scapulolunate ligament and is usually located between the extensor digitorum communis of the index finger and the extensor pollicis longus tendons. Intratendinous ganglion is very rare lesion that originates within the tendon, which has been reported 10 cases in earliest articles and 1 case in Korean article. We report one case of ganglion that arose within the extensor digitorum communis of the middle finger.