In recent years the use of epidural opiates has increased and although this method of pain relief has shown good results in clinical practice It is still subject to certain drawbacks, the most serious of which appears to be delayed respiratory depression. Since ketamine administered systemically is unlikely to produce respiratory depression it seemed worthwhile to investigate the possibility of exploiting the potent analgesic property to ketamine by its epidural administration. The analgesic effect of ketamine 4 mg, administered epidural space, was evaluated. The duration of pain relief varied from less than 3 hours in 20% to over 24 hours in 30% of the cases. In 62.5% of the cases pain relief exceeded 6 hours. There was no evidence of respiratory depression, and there no postoperative neurologic sequelae. The present results indicated the need for further studies to compare the efficacy and safety of epidural ketamine with the response to epidural opioids for the relief of postoperative pain.