The Authors report 8 cases of Failed Lumbar Disk Syndrome (FLDS), on 210 patients operated for slipped disk. Risk factors and the concept that an abnormality involving either neurons in the substantia gelatinosa or internucial fibers in Lissauer's tract is responsible for pain in patients with FLDS are discussed. Since iatrogenic deafferentation pain response to almost all current forms of therapy is generally poor, the most rational approach remains prevention.