Background and problemTo compare dinoprostone vaginal insert (PG) with cervical ripening balloon (CRB) as second line of cervical ripening in women at term with a persistent unfavorable cervix after first PG. MethodsThis retrospective cohort study comprised all women with singleton fetus in cephalic presentation who required cervical ripening at term (≥37 weeks) for maternal and/or fetal disease using repeated PG or CRB for a persistent unfavorable cervix (Bishop score <6) 24 h after first PG. Primary outcome was vaginal delivery rate. Secondary outcomes were favorable cervix (Bishop score ≥6) or labor within 24 h after second device placement, postpartum hemorrhage (PPH) and neonatal morbidity. Findings180 women were analyzed (127 repeated PG (70.6 %) and 53 CRB after first PG (29.4 %)). After second device, 93.3 % of women had a favorable cervix (Bishop score ≥6) or were in labor within 24 h, and the rate was significantly higher after CRB, compared to repeated PG (98.1 % vs. 91.3 %; p = 0.048). Vaginal deliveries were similar between groups (62.2 % after repeated PG vs. 54.7 % after CRB; p = 0.36). PPH was observed in 22.2 % of included women, and no difference was observed between groups (21.3 % vs. 21.4 %; p = 0.63). Neonatal morbidity was similar between groups (13.4 % vs. 9.4 %; p = 0.48). ConclusionVaginal delivery rate and neonatal morbidity were similar when using PG or CRB as second line in women at term with a persistent unfavorable cervix after first PG. CRB seemed to be more efficient on the cervix status, compared to repeated PG, in these women.