BACKGROUND: Perfluoroalkyl acids (PFAA) are repellants that cross the placental barrier, enabling interference with fetal programming. Maternal PFAA concentrations have been associated with offspring obesity and dyslipidemia in childhood and adulthood, but this association has not been stud-ied in infancy. OBJECTIVES: We investigated associations between maternal PFAA concentrations and repeated markers of adiposity and lipid metabolism in infancy. METHODS: In the prospective Odense Child Cohort, maternal pregnancy serum concentrations of five PFAA: Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were measured in 649 women. Offspring were examined at birth (n = 613) and at 3 months (n = 602) and 18 months (n = 503) of age. Total cholesterol, LDL, HDL, and triglyceride were evaluated at 3 months (n = 262) and 18 months (n = 198) of age. Mixed effects linear regression models estimated associations between PFAA and standardized (SDS) body mass index (BMI), ponderal index, and waist circumference. Associations between PFAA and body fat% (BF%) and plasma lipids SDS at 3 months and 18 months of age were investigated with linear regression models. RESULTS: PFNA and PFDA were associated with higher BMI SDS [adjusted b =0:26; 95% confidence interval (CI): 0.03, 0.49 and b =0:58; 95% CI: –0:03, 1.19, respectively, for 1-ng=mL increases] and ponderal index SDS (b =0:36; 95% CI: 0.13, 0.59 and b =1:02; 95% CI: 0.40, 1.64, respec-tively) at 3 and 18 months of age (pooled) in girls. Corresponding estimates for boys were closer to the null but not significantly different from estimates for girls. In boys and girls (combined), PFNA and PFDA were associated with BF% at age 3 months (for 1-ng=mL PFDA, b =0:40; 95% CI: 0.04, 0.75), and PFDA was associated with total cholesterol SDS at 18 months (b =1:06; 95% CI: 0.08, 2.03) (n = 83). DISCUSSION: Prenatal PFAA were positively associated with longitudinal markers of adiposity and higher total cholesterol in infancy. These findings deserve attention in light of rising rates of childhood overweight conditions and dyslipidemia.