BACKGROUND: Oxytocin is used for uterine contraction after delivery in cesarean sections. Doses of oxytocin vary widely, ranging from 5 20 IU by slow IV infusion. The aim of this study was to compare the effect of three different doses of oxytocin (5, 15, 25 IU) during elective cesarean section. METHODS: Thirty patients (ASA 1 and 2) undergoing elective repeated cesarean section were assigned to one of three groups. Group I received 5 IU, group II 15 IU, and Group III 25 IU of oxytocin after clamping of the umbilical cord. Linear analog scale (LAS) of 0 to 10 assessed by the surgeon for degree of uterine contraction was used at 5, 10, 15, 20, 25 and 30 min after delivery. Blood pressure (BP) and pulse rate (PR) of the patients, volume of blood mixed with amniotic fluid in suction jars (Vol in S.J.), weight of all gauzes soaked with blood (Wt of gauzes), difference in pre- and postoperative hematocrit (Change in Hct), induction to delivery (I-D) and delivery to closure of uterus (D-C) interval were also recorded. RESULTS: There were no significant differences in the degree of uterus contraction, BP and PR of the patients, Vol in S.J., Wt of gauzes, Change in Hct, I-D and D-C interval, in the three groups. CONCLUSIONS: Five IU of oxytocin is as effective as more doses in healthy parturients undergoing elective cesarean section with general anesthesia.