Adiposity is associated with C-reactive protein level in healthy 2-3 year-old children and with other markers of endothelial activation in adults, but data are lacking in very young children. Data from 491 healthy Hispanic children were analyzed. Mean age was 2.7 years (SD 0.5, range 2-3 years); mean body mass index (BMI) was 17.2 kg/m2 (SD 1.9) among boys and 17.1 kg/m2 (SD 2.1) among girls. E-selectin level was associated with BMI (R = 0.11; p < 0.02), ponderal index (p < 0.02), waist circumference (p = 0.02), fasting insulin (p < 0.02), and insulin resistance (p < or = 0.05); these associations remained significant after adjustment for age, sex and fasting glucose. sVCAM was also associated with BMI (R = 0.12; p < 0.05). These observations indicate that adiposity is associated with inflammation and endothelial activation in very early childhood.