Takayasu's arteritis (TA) is a chronic inflammatory arteritis of unknown etiology involving mainly the aorta and its major branches. The interleukin (IL) 1β and IL-1 receptor antagonist have been playing an important role as regulators of inflammation. We investigated whether the polymorphisms at the IL-1B and IL-1RN gene cluster were associated with the genetic susceptibility to develop TA. We analyzed the IL-1B, IL-1F10.3, and IL-1RN polymorphisms in a sample of 58 TA patients, and 248 clinically healthy unrelated Mexican individuals by 5' exonuclease TaqMan polymerase chain reaction. Polymorphic haplotypes were constructed after linkage disequilibrium analysis. We found increased frequencies of different polymorphisms (C allele and TC genotype of IL-1F10.3; TT genotype of IL-1RN.4; C allele and TC genotype of IL-1RN6.1; G allele of IL-1RN6.2 and haplotypes "1T" and "1C" of IL-RN VNTR and IL-1RN6.1) in the group of TA when compared to healthy controls. On the other hand, decreased frequency of IL-1-511 TC genotype was found in the TA group compared to controls. IL-1B and IL-1RN gene polymorphisms could be involved in the risk of developing TA in the Mexican population. These associations were independent of the affected vessels.