The purpose of this study was to examine the assocation between lactation and maternal visceral adiposity among US women who were on average 7 years postpartum. This cross-sectional analysis included 89 women who gave birth between 1997 and 2002, who did not have preeclampsia, prepregnancy hypertension or prepregnancy diabetes, and enrolled in The Women and Infant Study of Healthy Hearts (WISH). Computed tomography was used to assess abdominal adiposity. History of lactation was self-reported. Visceral adiposity was greater by 36.96 cm(2) (95% CI: 20.92,53.01) among mothers who never breastfed than mothers who breastfed for ≥3 months after every birth, even after adjustment for age, parity, years since last birth, site, socioeconomic, lifestyle, psychological, and family history variables, early adult BMI, and current BMI. Similarly, in fully adjusted models, mothers who breastfed any of their children for less than 3 months had 20.38 cm(2) (95% CI: 2.70, 38.06) greater visceral adiposity than mothers who consistently breastfed all their children for 3 or more months. This study found that 7 years postpartum visceral fat depots are significantly greater among mothers who lactated for less than 3 months after the birth of each of their children. These results provide a potential physiologic basis for prior findings that women who do not consistently breastfeed are at an increased risk of diabetes, cardiovascular disease, and the metabolic syndrome.