Objectives: To evaluate dose-related outcome of induction of labor (IOL) using misoprostol vaginal inserts (MVI) in multipara pregnant women so as to determine the appropriate dose for getting trial success defined as having vaginal delivery (VD) within 24-hr induction-to-delivery (ITD) interval. Patients & Methods: 644 pregnant women underwent clinical evaluation and vaginal examination to determine Bishop score using the Simplified Bishop Score (SBS). All women received 25 ?g MVI only once and were monitored for labor progress as judged by SBS and uterine contractions with fetal heart monitoring. In absence of fetal distress manifestations and membranes were still intact, but uterine contractions occurred <3 times/10 minutes, another MVI was used for a maximum of 6 doses. Uterine contraction augmentation was provided as amniotomy or/and oxytocin infusion started 4-hrs after the last MVI was placed. Study outcomes included trail success rate, number of MVI used, frequency and mode of augmentation and delivery assistance. Results: 530 women (82.3%) had VD; 159 women without augmentation, 182 women had amniotomy, 105 women received oxytocin drip and 84 women required both. Only 168 women (26.1%) had instrumentally-assisted VD. Mean ITD interval was 10.9?6.3 hr; 492 women had ITD interval <24 hr for a trial success rate of 76.4%. Cesarean section was indicted in 114 women (17.7%). Only 29 women received four, 71 three, 93 two, while 451 women received one MVI, VD rate was significantly (p<0.00001) lower among women received higher number of MVI. Statistical analyses defined high MVI dose and BMI as negative, while high parity is a positive significant predictor for trial success. High MVI dose and BMI are positive, while high SBS and high parity are negative significant predictors for long ITD interval. Kaplan-Meier regression analysis defined the appropriate MVI for IOL trial success at a mean dose of 1.5?0.039 (95% CI: 1.4-1.55). Conclusion: MVI is a satisfactory modality for IOL trial in multipara pregnant women with VD rate of 82.3% and ITD interval of <24-hr in 76.4%. Lower BMI and higher number of previous VD indicate higher possibility of trial success. SBS is appropriate for women selection for trial and follow-up and can predict outcome if combined with BMI, parity and number of MVI used.