Tarlov's cyst or perineurial cyst is disease on portion of the posterior nerve root in lumbo-sacral region. The lack of knowledge of physicians around the world about Tarlov's cyst as to their nature, significance and treatment also with differential diagnostics to radiculopathy in legs. With review of literature discuss about definition, etiopathogenesis, diagnostic investigation and treatment clinic and/or surgery. The pathogenesis Tarlov's cyst remains unclear; several cases have history of the trauma, old hemorrhage, congenital and iatrogenic. Cysts provoke low back pain, sacral radiculopathy, dyspareunia, urinary incontence. The magnetic resonance imaging is now the gold standard to diagnose cysts. The treatment is clinic or surgery depending neurologics finding and neuroimage.