OBJECTIVE To compare the safety and efficacy of 10 units of intravenous syntocinon alone with 10 units intravenous syntocinon and 0.25 mg intramuscular ergometrine in the prevention of atonic uterine haemorrhage during caesarean section. METHODS The quasi-experimental study was conducted at the Maternal and Child Health Centre, Unit I, Pakistan Institute of Medical Sciences, Islamabad, from November 1, 2010 to February 28, 2011. All women undergoing caesarean section were included in the study. Patients were given intravenous 10 units syntocinon alone intraoperatively from November 1 to December 31,2010, while 0.25 mg ergometrine intramuscular was added to 10 units intravenous syntocinon from January 1 to February 28, 2011. Frequency of postpartum haemorrhage, adverse effects of drugs and maternal morbidity and mortality were assessed by using chi square test. P < 0.05 was taken as statistically significant. RESULTS Of the total number of 701 subjects, 378 (54%) women were given 10 units syntocinon and 323 (46%) were given 0.25 mg ergometrine in addition to 10 units syntocinon. The mean age in the syntocinon group was 28 +/- 3.5 yrs with gestational age of 37.5 +/- 2 wks, while that in syntocinon-ergometrine group was 29 +/- 3.4 years and 38 +/- 2 weeks respectively. Postpartum haemorrhage in the syntocinon group was found in 38 (10%) women versus 05 (1.5%) women) in the other group (p < 0.001). Adverse effects like nausea, vomiting and raised blood pressure were slightly more with syntocinon-ergometrine than syntocinon alone (n = 56; 15.3% vs n = 35; 9.2%), but it was not statistically significant. Post partum haemorrhage was responsible for 40% of maternal mortality during the study period and that was in the syntocinon group. CONCLUSIONS Prophylactic ergometrine in addition to syntocinon is superior to syntocinon alone in decreasing frequency of postpartum haemorrhage in caesarean section and associated maternal morbidity and mortality. Regarding safety profile, the two groups showed no statistically significant change.