Interleukin-13 (IL-13) is known to be a key regulator in immunoglobulin E (IgE) synthesis, mucus hypersecretion and airway hyperresponsiveness. Single nucleotide polymorphisms in IL-13 are associated with allergic phenotypes in several ethnically diverse populations.This study was performed in 214 atopic patients (asthma n=108, allergic rhinitis n=106) and sex-matched healthy controls (n=120). Genotyping of IL-13 gene polymorphisms was performed using polymerase chain reaction-based restriction fragment length polymorphism method.A statistically significant association of the A-1512C polymorphism in IL13 gene was observed with atopy (p<0.001; Ï2=19.0). Upon stratification of the data into asthma and AR association was revealed with both asthma (p=0.01; Ï2=8.80) and AR (p<0.001; Ï2=24.3) in Pakistani patients. Higher odds ratio (OR 95% CI) was observed for AR 3.42 (2.04-5.76) relative to asthma 2.40 (1.41-4.09) for the C allele compared to controls.In conclusion the study provides the evidence A-1512C polymorphisms in IL-13 is a risk factor for asthma and AR.