Aim:To evaluate the association of three single nucleotide polymorphisms in TNF and one in LTA in Mexican patients with aspirin-exacerbated respiratory disease (AERD) and the correlation of those single nucleotide polymorphisms with serum levels of TNF-α. Patients & methods: Case-control study including 133 patients with AERD, 135 patients with asthma (aspirin-tolerant asthmatics) and 182 healthy subjects. Results: GA genotype of rs1800629 in TNF was found to be associated with the risk of developing AERD (p < 0.05; odds ratio = 2.36) and by dominant model (p < 0.05; odds ratio = 2.51). Furthermore, there was a difference in the serum levels between the aspirin-tolerant asthmatics group and the other groups (p < 0.001). Conclusion: The GA genotype of rs1800629 is associated with genetic susceptibility to AERD, but it does not correlate to protein serum levels. Aspirin-exacerbated respiratory disease (AERD) is a clinical disease characterized by hypersensitivity to aspirin, asthma and chronic rhinosinusitis with nasal polyps. It affects 10% of the population with asthma; however, its prevalence increases to 21% when provocation tests are used [1]. AERD is a disease characterized by restructuring of the airway [2] and the presence of extensive hyperplastic eosinophilic sinusitis with the formation of nasal polyps [3]. The most important clinical characteristic is bronchoconstriction after the administration of aspirin (ASA) or other nonsteroidal anti-inflammatory drugs (NSAIDs) [2,4]. The physiopathology involves a block in the cyclooxygenase pathway that promotes a diversion of arachidonic acid metabolism toward the lipoxygenase pathway, inducing the synthesis of leukotrienes such as LTC4, LTD4 and LTE4 [5,6], proteins that induce inflammatory cell chemotaxis, and the release of cytokines such as TNF-α [7] and lymphotoxin. TNF-α is a critical molecule in the regulation of inflammation because it induces a cascade of other inflammatory cytokines, chemokines and growth factors [8]. The results of various in vivo and in vitro studies indicate that the increase in their production is involved in the severity of the inflammation, due to their participation in restructuring the airway and in the pro-oxidative response [9]. In relation to single nucleotide polymorphisms (SNPs), it has been reported that rs1800629 (G→A change in position -308) increases transcriptional activity [10,11], in addition to being associated with different pulmonary pathological diseases such as chronic obstructive pulmonary disease and asthma [9,12,13]. However, no SNPs have been reported in TNF or LTA that are associated with AERD.