Epidural analgesia for pain relief during labour has certain disadvantages including slow onset. However, intrathecal sufentanil provides rapid onset and well-controlled analgesia lasting 1-4 h. The aim of this study was to compare the analgesia and the side effects of intrathecal sufentanil with epidural bupivacaine during labour. In a randomized, double-blind and controlled trial 58 parturient women requesting analgesia during labour were studied. The patients received either intrathecal sufentanil 10 micrograms and epidural saline, or intrathecal saline and epidural bupivacaine 20 mg. Visual analogue scores (VAS) for pain, blood pressure, heart rate, respiratory rate, level of sedation and the incidence of pruritus and nausea were recorded. Pain scores were significantly lower between 5 and 90 min after injection in patients receiving intrathecal sufentanil. Pruritus was significantly more frequent among those receiving intrathecal sufentanil. The rapid onset and effective analgesia of intrathecal sufentanil may in certain situations be advantageous.