Objective: Our purpose was to compare the efficacy of commercial prostaglandin E₂ products, in combination with oxytocin, for the initiation of labor among pregnancies with pre-eclampsia. Study Design: Patients with pregnancy-induced hypertension and with either proteinuria or other end-organ damage were enrolled if they had an unfavorable Bishop score (≤4) and were eligible to undergo labor. Each was randomly assigned to receive prostaglandin E₂ either as a 0.5-mg intracervical gel (Prepidil) or as a 10-mg controlled-release vaginal insert (Cervidil). Oxytocin was begun either immediately after instillation of the gel or was delayed until after removal of the insert. Results: Of the 70 patients, there were no differences between the Prepidil (n = 34) and the Cervidil (n = 36) groups in maternal demographics, gestational age, parity, and predose Bishop score. There was a mean 14.3-hour difference in the duration from beginning therapy until vaginal delivery in the Prepidil group than in the Cervidil group (11.5 ± 2.3 hours vs 25.8 ± 6.9 hours, P < .001). This time difference, which favored use of Prepidil–immediate oxytocin, remained significant after parity (nulliparous: 20 hours, P < .005; multiparous: 12 hours, P < .01) and gestational age were controlled (preterm: 15.5 hours, P < .01; term: 13.3 hours, P < .01). Conclusion: Use of combined intracervical prostaglandin E₂ gel–immediate oxytocin therapy was more effective in shortening the induction-to-vaginal delivery time than use of a controlled-release prostaglandin E₂ vaginal insert. (Am J Obstet Gynecol 1998;179:1204-9.)