The purpose of this study was to examine the association of short sleep duration among women in the first year postpartum with adiposity and cardiometabolic status at 3 years postpartum. We studied 586 women in Project Viva, a prospective cohort. At 6 months and 1 year postpartum, women reported the number of hours they slept in a 24-h period, from which we calculated a weighted average of daily sleep. We used multivariable regression analyses to predict the independent effects of short sleep duration (≤5 h/day vs. >5 h/day) on adiposity, glucose metabolism, lipid metabolism, and adipokines at 3 years postpartum. Women's mean (s.d.) hours of daily sleep in the first year postpartum was 6.7 (0.97) h. After adjusting for age, race/ethnicity, education, parity, prepregnancy BMI, and excessive gestational weight gain, we found that postpartum sleep ≤5 h/day was associated with higher postpartum weight retention (β 1.50 kg; 95% confidence interval (CI): 0.02, 2.86), higher subscapular + triceps skinfold thickness (β 3.94 mm; 95% CI: 1.27, 6.60) and higher waist circumference (β 3.10 cm; 95% CI: 1.25, 4.94) at 3 years postpartum. We did not observe associations of short sleep duration with measures of cardiometabolic status at 3 years postpartum. In conclusion, short sleep duration in the first year postpartum is associated with higher adiposity at 3 years postpartum.