Labor induction for medical reasons is a situation rather well-controlled by the combination: "oxytocin-amniotomy" when the cervix is favorably open. However, new induction techniques are currently under study, especially vaginal administration of PGE2 which presents the advantage of being simple to administer and better accepted by the patients. This study compared the classical technique, oxytocin perfusion and early artificial rupture of the membranes, with the vaginal administration of PGE2 gel (first dose: 1 mg, second dose 1 or 2 mg, six hours later). The success rate of both techniques is comparable, approximately 70 p. cent. Also, the times between amniotomy and delivery are identical, approximately 5 hours. On the contrary, the lapses of time between the onset of the induction and the delivery, vary significantly, being always longer in the PGE2 group. However, the dose of vaginal PGE2 gel as well as the time of artificial membrane rupture could be modified in order to decrease the delay of the effect.