Introduction: Previous publications have shown that glucose supplementation could reduce labor duration in women with induction of labor with a favorable cervix but none have shown it for women with an unfavorable cervix.  The purpose of our study was to assess the impact on labor duration of a protocol of glucose supplementation used for induction of labor in women with an unfavorable cervix. Material and methods: The protocol implemented in November 2017 added glucose supplementation by 5% dextrose at 125 mL/h to Ringer lactate for women with an unfavorable cervix with labor induced with dinoprostone gel. The study included women who underwent this protocol with a singleton, term, cephalic fetus from June 2017 through April 2018. The primary outcome was the labor duration. The secondary outcomes were mode of delivery, postpartum hemorrhage rate, neonatal outcomes, and durations other stage of labor. These outcomes were compared between the pre-intervention (from June 1 to October 31, 2017) and post-intervention (from December 1, 2017 to April 30, 2018) periods. Results: The pre-intervention period included 116 women, and the post-intervention period 123. The characteristics of women and the induction of labor were similar in the two periods. The median duration from induction to delivery was not significantly different between the two periods (13.2 h, IQR 9.1–18.6 versus 13.6 h IQR 9.3–18.3, P=.67). The secondary outcomes did not differ significantly between the two groups. Discussion: Glucose supplementation administered to women with an unfavorable cervix undergoing induction does not appear to reduce the induction-delivery duration.