In order to evaluate a dose-related response of cervical ripening and labor induction to a prostaglandin E2 (PGE2) gel, 110 women with uncomplicated postdate pregnancies and unripe cervices received intracervically 0.5 mg PGE2 (n = 40), 1.5 mg PGE2 (n = 35) or 2.5 mg PGE2 (n = 35). The failure rate in terms of cervical ripening was similar in all groups. Labor characteristics such as the duration of the latent phase as well as the total length of labor, the cesarean-section rate, instrumental deliveries and neonatal outcome were similar in all groups. The number of women who required oxytocin for labor augmentation was negatively correlated to the dose of PGE2 (p < 0.05). In addition, 3 out of 35 women in the 2.5-mg group presented hypertonic uterine activity. The increase in the dose of PGE2 gel did not increase the possibility for a vaginal delivery, but reduced the requirement for oxytocin while increasing hypertonic uterine action.