Since the term “facet syndrome” was introduced by Ghormley in 1933, arthropathy of the lumbar facet joint has long been recognized as an important source of low back pain, even sciatic pain. And facet joint injection has been helpful in the diagnosis and therapy for this facet syndrome. However, considering the possible complications such as infection, neurologic deficit and difficulty in locating the symptpmatic joint, and placebo effect, we have frequently doubted about clinical application of these procedures. This study is a retrospective review of 18 patients who got lumber facet joint injection for low back and leg pain with various previous indication that are not response to convential therapy for 2 months or more for therapeutic purpose. The response to facet joint injection was analyzed according to the entire spectrum of symptoms, physical findings, and X-ray findings. 13 or 15 patients with back pain with thigh or groin pain aggrevated by extension/rotation of trunk had successful response but patients with leg pain below the knee joint or pathology in the other structures in the spine got poor response. Strict diagnostic criteria through scoring system, provocation test, relief test and analysis of patient's signs and symptoms is needed to get higher degree of predictability and effectiveness of facet joint injection.