IL-13 is strongly implicated in the development of asthma and chronic obstructive polymonary disease (COPD). We previously identified an IL-13 promoter polymorphism (− 1055 C to T) that is associated with allergic asthma. We now report an increased frequency of the− 1055 T allele in COPD patients compared to healthy controls (P= 0.002) and compared to a second control group consisting of smoking individuals with normal lung function (P= 0.01). A closely linked IL-13 exon polymorphism is present at normal allelic frequencies (P= 0.3 and 0.4, respectively). In addition, we observed a normal distribution of two IL-4 polymorphisms at positions− 590 and+ 33 (P= 0.2 and 0.9, respectively). These results could implicate a functional role for the IL-13 promoter polymorphism in the enhanced risk to develop COPD.