We evaluated the influence of haplotypes of beta(2)-adrenergic receptor (ADRB2) polymorphisms on lung function and airway responsiveness (AR) in a pediatric cohort recruited before birth and followed up to 11 years of age. The subjects (180) were the participants in a prospective study of lung function and AR. They have been assessed five times (at 1 month, 6 months, 12 months, 6 and 11 years of age) for lung function and AR. The two ADRB2 single nucleotide polymorphisms (SNPs): Arg16Gly and Gln27Glu were genotyped by PCR-RLFP and their haplotypes inferred using the program PHASE. An association between the haplotype arg16gln27 and the prevalence of positive AR was found at age 6 years (P=0.009). The gly16gln27 haplotype was associated with higher FEV1 (P = 0.015) at age 6 and both higher FEV1 and FVC (P= 0.018 and P = 0.001, respectively) at age 11. In contrast, arg16gln27 was associated with both lower FEV1 and FVC (P = 0.028 and P = 0.011, respectively) at age 11. Children with the gly16gln27 haplotype were less likely to have asthma-ever or doctor-diagnosed asthma at age 11 (OR: 0.38; P=0.019 and OR: 0.31; P=0.041, respectively). In conclusion, haplotypes of beta(2)-adrenoceptor polymorphisms are associated with lung function, AR, and asthma susceptibility in childhood.