To assess the influence of several maternal and neonatal variables on the recurrence of gestational diabetes mellitus. Methods: A retrospective review was conducted on 90 of our patients whose index pregnancy was complicated by gestational diabetes mellitus and whose subsequent pregnancy was also managed at our institution. Results: Forty-seven women (52%) had a recurrence of gestational diabetes mellitus in their subsequent pregnancy. These 47 women had an increased body mass index (BMI) (32.8 ± 8.2 versus 28.9 ± 7.2 kg/m2; P <.03) and more large for gestational age (LGA) neonates (38 versus 14%; P <.05) and more of them required insulin during their index pregnancy (38 versus 19%; P <.05) than did those who did not have a recurrence of gestational diabetes mellitus. Women who developed a recurrence of gestational diabetes mellitus also had higher fasting (P <.05), 1-hour, 2-hour, and total glucose tolerance test values (P ≤.01) during their index pregnancy. Conclusion: Women with a history of gestational diabetes mellitus who have a BMI greater than 35 kg/m2, whose previous newborn was LGA, and who required insulin during their previous pregnancy are at increased risk for recurrence of gestational diabetes mellitus. (Obstet Gynecol 1992;80:755–8). © 1992 by The American College of Obstetricians and Gynecologists.