Objectives: The aim of the study was to compare the effectiveness of carbetocin and oxytocin for prevention of postpartum hemorrhage (PPH) after caesarean section. Material and methods: We analyzed data from 279 patients who received 100 μg of carbetocin intravenously or 10 IU of oxytocin into the uterine muscle as a rudimentary treatment for prevention of PPH. Results: Blood loss was statistically significantly higher (p=0.0136) in the entire study group as compared to the oxytocin group, and in cases when additional uterotonics were administered (p=0.0090). Also, we observed a statistically significantly correlation between the need for additional treatment and patient BMI. Patients with prepregnancy BMI of ≥ 25 more often required additional medicaments after administration of carbetocin as compared to oxytocin (p=0.0077). We noted a statistically significantly higher rate of using additional treatment (p<0.05) after administering oxytocin into the uterine muscle as compared to intravenously given carbetocin (75% vs. 33%, respectively). Conclusions: 1. Carbetocin is more effective than oxytocin in the prevention of PPH and significantly reduces the necessity to administer therapeutic uterotonics during caesarean delivery. 2. Higher rates of additional treatment with uterotonics after the administration of carbetocin as compared to oxytocin in a group of patients after 2 or more cesarean sections and women with BMI of ≥25 require further studies in a target-selected larger sample size. 3. Based on our findings, it is not possible to conclude that 100 μg of intravenous carbetocin is more effective than 10 IU of oxytocin given to the uterine muscle during caesarean delivery to prevent PPH.