Purpose To compare the effectiveness of cervical ripening by a mechanical method (double-balloon catheter) and a pharmacological method (prostaglandins) in women with one previous cesarean delivery, an unfavorable cervix (Bishop score < 6), and a singleton fetus in cephalic presentation. Methods This retrospective study, reviewing the relevant records for the years 2013 through 2017, took place in two French university hospital maternity units. This study included women with one previous cesarean delivery, a liveborn singleton fetus in cephalic presentation, and intact membranes, for whom cervical ripening, with unfavorable cervix (Bishop score < 6) was indicated for medical reasons. It compared two groups: (1) women giving birth in a hospital that uses a protocol for mechanical cervical ripening by a double-balloon catheter (DBC), and (2) women giving birth in a hospital that performed pharmacological cervical ripening by prostaglandins. The principal endpoint was the cesarean delivery rate. The secondary outcome measures were maternal and neonatal outcomes. Results We compared 127 women with prostaglandin ripening to 117 women with DBC. There was no significant difference between the two groups for the cesarean rate (42.5% in the prostaglandin group and 42.7% in the DBC group; p = 0.973; crude OR 1.01 [0.61-1.68]; adjusted OR 1.55 [0.71-3.37]). The median interval between the start of ripening and delivery did not differ between the groups (28.7 h in the prostaglandin group vs 25.6 h in the DBC group; p = 0.880). Neonatal outcomes did not differ between the groups, either. There was one case of uterine rupture in the prostaglandin group, with no associated maternal or neonatal morbidity. There were no neonatal deaths. The postpartum hemorrhage rate was significantly higher in the DBC group. Conclusion For cervical ripening for women with one previous cesarean, the choice of a pharmacological or mechanical protocol does not appear to modify the mode of delivery or maternal or neonatal morbidity.