Around the world, cancer patients often combine conventional anticancer treatment with complementary alternative medicines derived from natural sources such as fungi and mushrooms, including the popular lingzhi or reishi medicinal mushroom Ganoderma lucidum. Many studies to date have described the anticancer properties of G. lucidum, which are attributed to its major pharmacologically bioactive compounds, such as terpenoids and polysaccharides. Moreover, several scientific observations have suggested a potential beneficial therapeutic strategy using G. lucidum in combination with chemotherapeutic agents to improve therapeutic outcome. However, to my knowledge, no systematic review has been conducted in this area. Therefore, this review summarizes the current knowledge on G. lucidum or its individual components in relation to chemotherapeutic efficacy, ability to reverse multidrug resistance, and chemotherapeutic toxicity.