Ganglions are defined as cystic swellings closely connected to joints or tendon sheath, and contain mucinous material. Their most frequent site is the wrist and hand and occasionally they are found at ankle and knee. Some authors had reported rare cases of ganglion occured near the elbow joint which showed neurologic symptom by compressing the ulna nerve. We experienced two cases of ganglion which had occured at the elbow joint. Neurological symptoms were developed by compressing the ulna and radial nerve each sround the elbow joint.