A prospective, randomised, double-blind trial was conducted to study the effect of epidural morphine in prevention of post dural puncture headache in 25 parturients after inadvertent dural puncture. Women were randomly allocated to receive two epidural injections, 24 h apart, of either 3 mg morphine in 10 ml saline (morphine group) or 10 ml saline (saline group). The incidence of headache and need for therapeutic epidural blood patch were reported. There was a significant difference in the incidence of headache between the two groups: 3/25 (12%) in the morphine group and 12/25 (48%) in the saline group (p = 0.014). Therapeutic epidural blood patches were required in six patients in the saline group and none of the patient in the morphine group (p = 0.022). It was concluded that epidural morphine appears to be a simple and effective technique for prevention of post dural puncture headache after accidental dural puncture in high risk obstetric patients.