ABSTRACT. We investigated the association between the interleukin 4 gene (IL-4) -590C>T polymorphism and forced expiratory volume in one second (FEV 1 ) values, immunoglobulin E (IgE) levels, and susceptibility to asthma in Uighur children. IL-4 -590C>T frequencies were analyzed in 38 bronchial asthmatic patients and 35 non-asthmatic controls. Polymerase chain reaction and direct sequencing were applied to determine the residue at position -590 of IL-4. Total serum IgE levels were detected by enzyme-linked immunosorbent assay, while lung function was examined by professionals. There were significant differences in the distribution of IL-4 -590C>T genotypes and alleles between patient and control groups (genotypes: chi-square = 11.476, P < 0.05; alleles: chi-square = 14.572, P < 0.05). Frequencies of CC, CT, and TT genotypes were 21, 29, and 50% among patients, and 49, 37, and 14% among controls, respectively, indicating that the T allele was significantly more frequent in the asthma group than in the control group. Total serum IgE levels were significantly higher (P < 0.05) and FEV 1 values were significantly lower (F = 13.294, P < 0.05) in patients than in control subjects of the same genotype. In conclusion, the IL-4 -590C>T polymorphism is related to bronchial asthma in Uighur children, and the T allele may constitute a susceptibility factor in this group. Furthermore, this genetic variant can result in raised IgE levels and decreased FEV 1 values, suggesting that both factors are associated with bronchial asthma in Uighur children.