While Horner's syndrome is a rare and occasionally reported complication of epidural 'top-ups' administered for labour and Caesarean delivery, the case reported here followed a low-dose epidural infusion of bupivacaine. Low-dose epidural infusions have generally been regarded as a safer alternative to bolus doses in labour. It is also the case that close supervision is deemed unnecessary in some centres where the mother is receiving such an epidural infusion. This case is reported in order to highlight the potential dangers of a low-dose regime which in spite of the lack of early warning signs may be associated with a high block.