Background: Many cytokine genes contain polymorphic sites, some of which have been shown to affect transcription in vitro. The aim of this study was to determine whether cytokine polymorphisms affect circulating levels of cytokines after abdominal aortic aneurysm (AAA) repair. Methods: Seventy-four patients undergoing elective AAA repair had blood samples taken at induction of anaesthesia and 24 h after surgery. Plasma interleukin-6 and tumour necrosis factor-alpha (TNF-α) levels were determined by ELISA. Genotypes for the single-nucleotide polymorphisms at the following loci were determined using induced heteroduplex genotyping: IL-6-174 and TNF-α-308. Patient cytokine genotypes were compared with their baseline phenotypes and the change in cytokine levels between induction and 24 h postoperatively. Cytokine levels are expressed as mean (SEM) or median (range). Results: Patients with a IL-6-174 ‘G’ allele (56 patients, 77 per cent) had higher mean baseline plasma levels of IL-6: 16.06 pg/mL (9.7) versus 0.849 pg/mL (0.85), P = 0.124; and the mean change in plasma IL-6 between induction and 24 h was also higher for these patients: 370.55 pg/mL (46.87) versus 290.44 pg/mL (37.11), P = 0.185. Those patients with a TNF-α-308 ‘A’ allele (26 patients, 35 per cent) had higher median baseline plasma levels of TNF-α: 2.49 pg/mL (0–163.5) versus 0.0 pg/mL (0–159.57), P = 0.196, and the mean change in plasma TNF-α between induction and 24 h was also higher for these patients: 24.67 pg/mL (12.67) versus 17.06 pg/mL (7.09), P = 0.60. Conclusion: Cytokine genotype may affect in vitro cytokine production in the resting physiological state and in response to surgical stress.