Metabolic fitness in childhood is of increasing concern in transitional and advanced economies as the metabolic syndrome (MS) is recognized more often in this age group. As the MS appears, so also does hyperuricemia. Studies in Taiwan have identified both indigenous and Chinese with high prevalence of hyperuricemia. Data (1227 boys and 1057 girls, aged 6-12) from the Nutrition and Health Survey in Taiwan Elementary School Children (NAHSIT Children 2001-2002) were used to appraise the association between uric acid (UA) and MS in children. Mean serum urate increases by age, ranging from 5.69 mg/dL to 7.11 mg/dL for boys and 5.61 mg/dL to 6.13 md/dL for girls. Boys have higher UA concentrations (6.07 mg/dL vs. 5.74 mg/dL) and hyperuricemia (UA > or = 7 mg/dL) rate (26.5% vs. 18.8%) than girls. Children of Mountain areas have higher rates of hyperuricemia (boys: 39.2%, girls: 30.1%). 5.56% of boys and 6.39% of girls were classified as having the MS by ATP III criteria. Serum urate was closely correlated with the MS parameters, and waist circumference (WC) in particular (r=0.387). WC alone accounted for 18% of variance of serum urate concentration. Both serum urate and hyperuricemia are significant risk factors for the MS (serum urate in mg/dL, OR: 1.54, 95% CI: 1.36-1.74; hyperuricemia, OR: 3.73, 95% CI: 2.47-5.62). Adjustment for age and region accentuate these relationships. Not only abdominal fatness, but also uric acid status, or both together may be of interest to public health workers and clinicians in regard to the transitional health problem of MS.