The genetic variability (polymorphisms) can be a factor in COPD risk. We investigated the potential relationship between COPD and polymorphism of the interleukin 4 (IL-4 70 bp repeats) gene. In our study we observed the association between IL-4 (70 bp repeats) genotypes and COPD risk. A total of 400 subjects (200 cases and 200 controls). Using a case control design individuals were genotyped for IL- 4 using polymerase chain reaction (PCR) and restriction fragment length polymorphism techniques. The data obtained were analyzed using multiple logistic regressions by the help of SPSS ver 11.5. The OR of combined genotype of IL-4(Rp1-Rp2+Rp1) was showed 2 fold increase risk of COPD. In smokers, 5 fold significantly increased risk of COPD was observed with Rp1 genotype of IL-4. The genetic polymorphism in cytokine and IL-4 (70 bp repeats) gene may play an important role in the development of COPD.