To compare the impact of induction of labor at 38weeks of gestation with the induction of labor at 40weeks of gestation in women with insulin-treated gestational diabetes on maternal and fetal outcome. In this study 100pregnant women with insulin-treated gestational diabetes were randomized to either induction of labor at 38(groupI) or 40weeks (groupII) to evaluate the rate of large for gestational age newborns, neonatal hypoglycemia, success rate of deliveries within 48h and cesarean section rate after induction in both groups. The difference of large for gestational age newborns was not significant between the two groups (6.8% vs. 12.8%, p= 0.49), 16(36.4%) newborns in groupI and 8(17.0%) newborns in groupII developed hypoglycemia <35 mg/dl (p= 0.04). The success rate for deliveries within 48h after induction of labor for groupsI andII was 77.3% and 92.3%, respectively (p= 0.25). The cesarean section rate after induction of labor was not significantly different between the two groups (24.1% vs. 18.7%, p= 0.49). In acohort of women with insulin-treated gestational diabetes, induction of labor at 38weeks did not significantly reduce the rate of large for gestational age newborns compared to induction at 40weeks but seems to increase the rate of neonatal hypoglycemia.