Background: In 2015, a quality improvement project of childbirth care called Adequate Birth Project (“Projeto Parto Adequado”- PPA) was implemented in Brazilian public and private hospitals, aiming to improve the quality of childbirth care and to reduce cesarean sections without clinical indications. The objective of this study is to conduct an economic analysis of two models of care existing in a private Brazilian hospital - the model following the recommendations of the PPA and the standard of care model - in reducing the proportion of cesarean sections. Methods: We conducted a case study in one of the private hospitals included in the PPA project. The main outcome was the proportion of cesarean section. We used total cost of hospitalization for women and newborns, from the perspective of the health care provider, during the length of the observed hospital stay. We did not apply discount rates and inflation rate adjustments due to the short time horizon. We conducted univariate sensitivity analysis using the minimum and maximum costs observed in hospitalizations and variation in the probabilities of cesarean section and of maternal and neonatal complications. Results: 238 puerperal women were included in this analysis. The PPA model of care resulted in a 56.9 percentage point reduction in the cesarean section probability (88.6% vs 31.7%, p <0.001) and an increase in the total cost of US$ 67,346.25, which an incremental cost-effectiveness ratio of US$ 1,183.59 per avoided cesarean section. Women in the PPA model of care also had a higher proportion of spontaneous and induced labor and a lower proportion of early term births. There were no maternal, fetal or neonatal deaths and no significant differences in cases of maternal and neonatal nearmiss. The cost of uncomplicated vaginal births and cesarean sections was the parameter with the greatest impact on the cost-effectiveness ratio of the PPA model of care. Conclusion: The quality improvement project of childbirth care “PPA” was cost-effective in reducing cesarean sections in women assisted in a Brazilian private hospital, without increasing severe negative maternal and neonatal outcomes and reducing the frequency of early term births.