Intraosseous ganglia are benign cysts that usually can be seen in lower extremity; especially around ankle. These cysts have fewer incidences in upper extremity, mainly around the wrist. They are extremely rare in olecranon. These lesions are often asymptomatic. Patient was a 75-year-old man who had trauma many years ago. When he came to our clinic, he complained of severe pain around his elbow that he could not do ordinary activity. He had local tenderness in elbow and 30 degree limitation in extension. In radiography, lytic, multiloculated lesion existed in region of olecranon. After excisional biopsy was done, cavity was cleaned completely with curette and was filled with autogenous bone. At 10-year follow-up, the patient was completely asymptomatic. Control radiograph showed cavity filled completely by bone; there was no evidence of relapse.