BACKGROUND AND AIM: Prenatal metal exposure influences child health. We evaluated associations between prenatal metals and childhood adiposity. METHODS: Six nonessential (As, Ba, Cd, Cs, Hg, Pb) and four essential metals (Mg, Mn, Se, Zn) were measured in first trimester red blood cells from Project Viva participants. Sum of skinfold thicknesses (SST) (mm) (N=859), waist circumference (cm) (N=882), and body mass index (BMI) z-score (N=875) were measured at early childhood. In mid-childhood and late teen, SST (N=747-715), WC (N=748-717), BMI (N = 745-716), and dual-energy x-ray absorptiometry total- and trunk-fat-mass-index (kg/m2) (N=599-511) were measured. Linear regression and quantile g-computation models estimated associations between individual and mixtures of metals and adiposity, adjusting for confounders. RESULTS:Higher levels of prenatal cadmium were associated with increased SST at early childhood (β=0.30, 95% CI: 0.02, 0.58), and higher total (β=0.25, CI: 0.02, 0.48) and trunk fat (β=0.12, CI: 0.01, 0.23) at early teen. Cesium was associated with higher BMI at mid-childhood (β=0.18, CI: 0.02, 0.35) and trunk fat at early teen (β=0.24, CI: 0.003, 0.48). In mixture analyses, with concurrent adjustment for nonessential and essential metals, higher levels of prenatal nonessential metals were associated with higher total (β=0.07 per quartile, 95% CI: 0.01, 0.12), trunk fat (β=0.12, CI: 0.02, 0.22), WC (β=0.01, CI: 0.002, 0.01), and BMI (β=0.24, CI: 0.08, 0.41) at mid-childhood and higher total fat (β=0.06, CI: 0.002, 0.11) and BMI (β=0.19, CI: 0.02, 0.37) at early teen, while higher prenatal essential metals were associated with lower total (β=-0.07, CI: -0.12, -0.02), trunk fat (β=-0.13, CI: -0.21, -0.05), SST (β=-0.08, CI: -0.14, -0.01), WC (β=-0.03, CI: -0.05, -0.003), and BMI (β=-0.16, CI: -0.28, -0.04) at early teen. CONCLUSIONS:Prenatal nonessential metals were associated with increased adiposity, while essential metals were associated with decreased adiposity during childhood. KEYWORDS: Heavy metals, Obesity and metabolic disorders, Mixtures analysis, Children's environmental health