Due to the advances made in the field of natural products in the search for new molecules, mushrooms are gaining importance due to their bioactive compounds. These bioactive compounds have been shown to exhibit new modes of action against various diseases. As a result, a new class of mushroom pharmaceuticals is being established. Many species of mushrooms have been very well explored in terms of their biological and nutraceutical properties; however, there are still many species that remain unexplored and need to be studied to determine their medicinal and biological properties. Therefore, their proper identification and experimental studies are required to establish their pharmaceutical potential. In this chapter, a few lesser-known species of mushrooms are described, alongside their chemistry and biological properties that have been reported to date.