The inflammatory microenvironment that is enriched with inflammatory cells, cytokines and chemokines can induce cell proliferation and mutation, and thereby provides possibility of growth, migration and immune evasion for tumors. Interleukin-6 (IL-6) is a multifunctional inflammatory factor produced by immune cells, which plays an important role in the inflammatory reactions, immune responses and hematopoietic regulation. More and more studies have found that IL-6 plays a key role in the development and progression of many cancers. In this paper, the authors address the recent progress concerning the relationship between IL-6 and digestive tract tumors.