In recent years, pro-oncogenic mechanisms of the tumour microenvironment (ТМЕ) have been actively discussed. One of the main cytokines of the TМЕ is interleukin-1 beta (IL-1β), which exhibits proinflammatory properties. Some studies have shown an association between an increase in IL-1β levels and tumour progression. The purpose of this review is to analyse the pathogenic mechanisms induced by IL-1β in the TМЕ, as well as the diagnostic significance of the presence of IL-1β in patients with cancer and the efficacy of treatment with IL-1β inhibitors. According to the literature, IL-1β can induce an increase in tumour angiogenesis due to its effects on the differentiation of epithelial cells, pro-angiogenic molecule secretion and expression of adhesion molecules, thus increasing tumour growth and metastasis. IL-1β is also involved in the suppression of anti-tumour immune responses. The expression and secretion of IL-1β has been noted in various types of tumours. In some clinical studies, an elevated level of IL-1β was found to be associated with low efficacy of anti-cancer therapy and a poor prognosis. In most experimental and clinical studies, the use of IL-1β inhibitors contributed to a decrease in tumour mass and an increase in the response to anti-tumour drugs.