Synovial cysts are a common complication of osteoarthritis in the lumbar spine, causing pain and neurological symptoms. However with early diagnosis a good clinical result can be expected. This report describes a documented case of hemorrhage into a synovial cyst demonstrated on both MR and CT imaging and summarizes the relevant diagnostic features. The sites of origin of such a synovial hemorrhagic cyst are described and its relationship to an arthritic facet joint is stressed.