The effects of postpartum weight retention on gestational weight gain in successive pregnancies require elucidation. The purpose of the study was (1) to examine the association between postpartum weight retention and subsequent adherence to the Institute of Medicine gestational weight gain guidelines and (2) to determine whether the association varies by body mass index status and affects birth outcomes. Florida vital records for 2005-2010 were analyzed using χ2 tests and multivariable Poisson regression, adjusted for interpregnancy interval, tobacco use, maternal age, and race/ethnicity. Obese women who gained inadequate weight were more likely to retain weight between pregnancies than obese women who met or exceeded the recommended weight gain. Risks for preterm birth increased among women with inadequate weight and decreased among women with excessive weight gain. Gaining excessive weight was protective for small-for-gestational age infants in all body mass index categories but increased the risks for large-for-gestational age infants. Underweight and normal weight women who gained in excess were 40% more likely to develop hypertension than normal weight women who gained within the recommended amount. Obese women who retain or gain weight postpartum are at increased risk for inadequate weight gain in a successive pregnancy. Achieving Institute of Medicine–recommended gestational weight gain is essential for preventing adverse maternal and infant outcomes.