Intrathecal drug delivery (ITDD) has been an option for the management of persistent pain since the 1980s. The discovery of opioid receptors in the central nervous system was the impetus for early attempts to deliver opioids intraspinally. Approximately, 10-20 percent patients with cancer pain get inadequate analgesia from conventional medical management; this group particularly may benefit from ITDD. However, there is also some evidence for the use of ITDD in those with noncancer pain. This review presents options for ITDD, available drugs, evidence for efficacy, principles of patient selection, and problems with the intrathecal route.