Cancer is a leading cause of death worldwide. Recently, the demand for more effective and safer therapeuticagents for the chemoprevention of human cancer has increased. As a white rot fungus, Inonotus obliquus is valuedas an edible and medicinal resource. Chemical investigations have shown that I. obliquus produces a diverse rangeof secondary metabolites, including phenolic compounds, melanins, and lanostane-type triterpenoids. Amongthese are active components for antioxidant, antitumoral, and antiviral activities and for improving humanimmunity against infection of pathogenic microbes. Importantly, their anticancer activities have become a hotrecently, but with relatively little knowledge of their modes of action. Some compounds extracted from I. obliquusarrest cancer cells in the G0/G1 phase and then induce cell apoptosis or differentiation, whereas some examplesdirectly participate in the cell apoptosis pathway. In other cases, polysaccharides from I. obliquus can indirectlybe involved in anticancer processes mainly via stimulating the immune system. Furthermore, the antioxidativeability of I. obliquus extracts can prevent generation of cancer cells. In this review, we highlight recent findingsregarding mechanisms underlying the anticancer influence of I. obliquus, to provide a comprehensive landscapeview of the actions of this mushroom in preventing cancer.