We undertook a systematic review to determine the optimal dose of oxytocin after elective caesarean section or caesarean section in labouring women. We identified seven trials. These trials raise questions about the use of high dose (10 international units; IU) or moderate dose (5 IU) oxytocin in both settings and provide evidence that lower doses are equally effective but associated with significantly fewer side-effects. For elective caesarean section, a slow 0.3 to 1 IU bolus of oxytocin over one minute, followed by an infusion of 5 to 10 IU.h(-1) for four hours represents an evidence-based approach to dosing for women at low risk of postpartum haemorrhage. For the labouring parturient a slow 3 IU bolus of oxytocin, followed by an infusion of 5 to 10 IU.h(-1) for four hours is supported by limited evidence. These doses represent a starting point in the control of postpartum haemorrhage after caesarean section and do not reduce the need for mandatory active observation of the clinical situation, to detect situations that require additional doses of oxytocin or other uterotonic drugs. These doses of oxytocin minimise the risk of adverse haemodynamic changes as well as the unpleasant side-effect of nausea.