Research suggests that weight cycling is associated with difficulty losing or maintaining weight and thus may be a risk marker that will presage overweight/obesity. Most women retain weight after pregnancy but it is uncertain if a history of weight cycling influences weight retention 6-24 months after delivery (mean = 321 days, standard deviation = 79). The literature also suggests an ethnic difference in the amount of retained weight. The study group included new mothers whose infants received well-baby care at the Naval Medical Center, San Diego from 1997 to 1999. Women were categorized as never losers (n = 441), weight loss maintainers (n = 217), or cyclers (n = 702); data were analyzed by multivariable linear regression. After adjusting for 8 covariates and time since birth, cycling was significantly associated with increased weight retention (multiple regression coefficient = 1.9 kg (standard error [se] = 0.44, p < 0.01) compared with the other groups. There were 813 White, 177 Black, 152 Asian, and 218 Hispanic mothers. Prevalence (%) of weight cycling was 53.4, 46.3, 46.7, and 52.8, and mean postpartum weight retention was 4.2 kg, 4.0 kg, 3.6 kg, and 4.6 kg in each of these groups, respectively. After adjustment, the multiple regression coefficients for weight cycling were 1.7 kg (se = 0.58, p = 0.003) for Whites, 3.3 kg (se = 1.4, p = 0.02) for Blacks, 1.8 kg (se = 0.97, p = 0.07) for Asians, and 1.1 kg (se = 1.2, p = 0.33) for Hispanics. Thus, weight cycling appears to be a risk factor for increased postpartum weight retention but ethnic factors, possibly behavioral in nature, do seem to modify this relationship.