AIM: The aim of this study was to assess maternal characteristics as predictors of inadequate or excessive gestational weight gain (GWG) and to characterize maternal and neonatal outcomes associated with inadequate or excessive GWG in Asian women. MATERIAL AND METHODS: A study was conducted among 1166 Chinese, Malay, and Indian women who delivered a live singleton infant at KK Women's and Children's Hospital, Singapore. Logistic regression analysis was used to determine predictors and maternal and neonatal outcomes of inadequate or excessive GWG, relative to adequate (recommended) GWG. RESULTS: While maternal age less than 20 years, Malay ethnicity and underweight pre-pregnancy body mass index increased the risk of inadequate GWG, overweight pre-pregnancy body mass index decreased this risk. Tall stature and Malay ethnicity were associated with an increased risk of excessive GWG, while maternal age greater than 30 years was associated with a decreased risk. Inadequate GWG increased the risk of preterm birth and decreased the risk of delivery by cesarean section and postpartum weight retention at 6 months. Excessive GWG increased the risk of delivery by cesarean section, postpartum weight retention at 6, 12 and 24 months and having a high-birthweight baby. CONCLUSION: Maternal predictors and perinatal outcomes of GWG among Asian women are similar to those identified previously among Caucasian, African-American and Hispanic women.