Abstract--Leptin, homocysteine (Hcy), and C-reactive protein are risk factors potentially useful in predicting future cardiac events. These plasma biomarkers may participate in the regulation of cardiovascular function through an NO-dependent mechanism. Our purpose was to investigate whether alterations in C-reactive protein, Hcy, leptin, and NO are present in small-for-gestational-age children and to determine whether the levels of these plasma biomarkers are associated with birth weight, vascular function, and blood pressure. Concentrations of leptin, Hcy, C-reactive protein, and NO were measured in 69 children (36 boys and 33 girls; ages 8 to 13 years). Leptin (means difference: 1.4 ng/mL; 95% CI: 0.4 to 2.4) and Hcy (means difference: 0.9 µmol/L; 95% CI: 0.3 to 1.5) levels were significantly elevated in children born small for gestational age compared with those with appropriate birth weight. Nevertheless, NO (means difference: 342.9 µmol; 95% CI: 124.2 to 561.6) concentration was significantly reduced in small birth weight children, and the levels of C-reactive protein remained unchanged. There was a significant association between the circulating levels of both NO and Hcy with vascular function, as well as with blood pressure levels, in our population. Because both Hcy and NO are associated with a risk of cardiovascular disease, it is possible that part of the association of low birth weight with elevated risk for vascular and metabolic disease in later life is mediated by perturbation in pathways for these biomarkers.