The present study aims to determine the role of immunomodulatory fungi for the treatment of cancer as an alternative way. Mushrooms have been part of human culture for thousands of years, many cultures especially from the East, recognized that the extracts of certain fungi could have great health benefits. Recent research has focused on identifying compounds that can modulate, positively or negatively, the biological responses of immune cells. These compounds stimulate immunity, and not only for the treatment of cancer, but also for immunodeficiency diseases; for drug-induced generalized immune suppression; for therapy combined with antibiotics and as adjuvant for vaccines. The medicinal mushrooms are considered as immunomodulators, they are able to regulate the immune system. A diverse collection of bioactive polysaccharides, glycoproteins, glycopeptides, and proteoglycans have an effect on the proliferation and differentiation of immune cells and cytokines. Different purified polysaccharides have had clinical use in Japan, China, and Korea for many years, without reports of negative effects in the short term or in the long term. Different studies have shown that the application of polysaccharide extracts can have a cancer prevention effect and a restriction of tumor metastasis; they have also been used to treat microbial and viral infections, cardiovascular diseases and diabetes.