Ligamentum flavum hematoma is a rare spinal epidural hematoma whose pathogenesis is still unclear. It may be caused by the rupture and bleeding of the proliferative small vessels in the degenerative ligamentum flavum elicited by slight trauma. It was first reported by Professor Sweasy in 1992. It is mostly seen in the lumbar spine. The clinical symptoms are progressive aggravation, similar to intervertebral disc herniation and synovial cysts, and the main manifestation is the compression of nerve and dural sac. This paper reported a case of lumbar ligamentum flavum hematoma and reviewed the published literature.