Midwife-led units have been shown to be safer and reduce interventions for women at low risk of complications at birth. In 2017, the first alongside birth center was opened in Spain. The aim of this study was to compare outcomes for women with uncomplicated pregnancies giving birth in the Midwife-led unit (MLU) and in the Obstetric unit (OU) of the same hospital. Retrospective cohort study comparing birth outcomes between low-risk women, depending on their planned place of birth. Data were analyzed with an intention-to-treat approach for women that gave birth between January 2018 and December 2020. A total of 878 women were included in the study, 255 women chose to give birth in the MLU and 623 in the OU. Findings showed that women in the MLU were more likely to have a vaginal birth (91.4%) than in the OU (83.8%) (aOR 2.98 [95%CI 1.62-5.47]), less likely to have an instrumental delivery, 3.9% versus 11.2% (0.25 [0.11-0.55]), to use epidural analgesia, 19.6% versus 77.9% (0.15 [0.04-0.17]) and to have an episiotomy, 7.4% versus 15.4% (0.27 [0.14-0.53]). There were no differences in rates of postpartum hemorrhage, retained placenta, or adverse neonatal outcomes. Intrapartum and postpartum transfer rates from the MLU to the OU were 21.1% and 2.4%, respectively. The high rate of obstetric interventions in Spain could be reduced by implementing midwife-led units across the whole system, without an increase in maternal or neonatal complications.