We investigated the association between single nucleotide polymorphisms (SNPs) and haplotype of the beta(2)-adrenergic receptor (ADRB2) gene and parameters of the metabolic syndrome in Korean adolescents. Body mass index, waist circumference, blood pressure, fasting glucose, triglycerides and high-density lipoprotein (HDL) cholesterol, free fatty acid and insulin, and homeostasis model assessment (HOMA) score were measured in 134 volunteer adolescents (69 male and 65 female). All subjects were genotyped for 5 SNPs: A-->G rs1042713 (Arg16Gly), C-->G rs1042714 (Gln27Glu), G-->A rs1042717 (Leu84Leu), C-->A rs1042718 (Arg175Arg), and G-->C rs1042719 (Gly351Gly). After adjustment for age and sex, we found that the rs1042717 SNP was associated with higher body weight, fasting insulin, and HOMA score. The rs1042714 SNP was associated with higher body fat, waist circumference, and free fatty acids; and the rs1042719 SNP was associated with higher diastolic blood pressure. The C-A-A-C haplotype at SNPs rs1042714, rs1042717, rs1042718, and rs1042719 was associated with higher body weight, fasting insulin, and HOMA score; the G-G-C-G was associated with higher body fat and waist circumference; the C-G-C-G was associated with lower HDL cholesterol; and the C-G-C-C was associated with lower body weight, lower waist circumference, and higher HDL cholesterol. In conclusion, these findings suggest that the genotypes and haplotypes of ADRB2 may influence parameters of the metabolic syndrome in Korean adolescents.