Background: Interleukin 2 (IL2) is a significant factor activating T-cell-mediated immune response by stimulation of natural killer cells, T-cells and in development of regulatory T (Treg) cells. Recent studies have that IL2 participates in cancer development by modifying the local immune response. Based on the suggested role of the single nucleotide polymorphisms (SNPs) rs2069762, rs6822844 and rs11938795 of IL2 in the pathogenesis of certain diseases, the relationship of these SNPs with clinicopathological variables and their possible implication for prognosis and disease outcome were evaluated in a cohort of Swedish patients with colorectal cancer (CRC). Materials and Methods: TaqMan SNP genotype assays based on polymerase chain reaction were used for analysis of the IL2 SNPs in 467 patients with CRC and 467 healthy controls. Expression analysis of IL2 in plasma and CRC tissue was also performed. Results: The allelic variants T in rs11938795 and G in rs6822844 were significantly associated with a higher risk of CRC. Kaplan-Meier analysis showed that cancer-specific survival was worse for individuals with C allele for rs2069762 with stage II CRC and with T allele for rs6822844 with stage III CRC. Conclusion: SNPs rs2069762, rs6822844 and rs11938795 of the IL2 gene may be helpful as prognostic biomarkers in the follow-up and management of the patients.