In this paper, we reviewed the findings from previous studies on the anti-tumor efficacy of inonotus obliquus, one of the most famous edible and medical fungi, in Russia and the former Soviet Union since the 1950s. To be specific, the findings from clinical researches regarding the medicinal benefits of inonotus obliquus for treating gastric cancer, esophageal cancer, lung cancer, laryngeal cancer, breast cancer, and leukemia have been summarized, indicating inonotus obliquus may relieve symptoms, improve immune and neural function, improve life quality, and may prolong survival in the cancer patients.