I read with interest the work by Al-metwalli [1] suggesting that epidural morphine reduced the incidence of postdural puncture headache in parturients receiving epidural analgesia. I believe I may have also detected a similar effect from intrathecal diamorphine in preventing postdural puncture headache following spinal anaesthesia. As evidence I would like to report my results from a 9-year prospective audit (1998–2006) of spinal anaesthesia complications in patients undergoing Caesarean section. In our obstetric unit we have a strict follow up policy where all patients receiving spinal anaesthesia are visited by an anaesthetist for a minimum of two postoperative days. One aim of this policy is to monitor the incidence of postdural puncture headache from year to year. From 1998 to 2002 the annual incidence of postdural puncture headache in patients undergoing Caesarean section under spinal anaesthesia was 1–2% but this figure appeared to fall sharply during the period 2003 to 2006. The only significant change in our practice in the latter period was that in late 2002 we introduced the use of intrathecal diamorphine into spinal anaesthesia for caesarean section. The type of spinal needle (25G Whitacre) used in our obstetric unit during the entire audit period remained constant. I presented my results at our department audit meeting and at that time postulated that intrathecal opioids might prevent postdural puncture headache. I then analysed every spinal anaesthetic chart during the 9-year period and divided the Caesarean section population into three groups: 1) no intrathecal opioid administered; 2) intrathecal fentanyl 10–20 μg; 3) intrathecal diamorphine 300 μg. The few cases where a spinal needle different to the 25G Whitacre had been used were excluded. The results are displayed in the table below (Table 1). A total of 5173 patients received spinal anaesthesia for caesarean section during the audit period, of which 4559 were followed up postoperatively. The results appear to suggest that intrathecal diamorphine (but not fentanyl) reduces the incidence of postdural puncture headache after spinal anaesthesia. A previous study also demonstrated that intrathecal fentanyl did not reduce the risk of postdural puncture headache with a 25G Quincke needle [2]. In addition to Al-metwalli’s study there have been other reports of epidural morphine preventing headache after accidental dural puncture [3, 4]. I have however, been unable to find any references to the effect of intrathecal diamorphine on the incidence of postdural puncture headache following spinal anaesthesia. As intrathecal diamorphine is now commonly used in many hospitals in the United Kingdom, I would be interested to hear if anyone else has noticed this additional potential benefit.