The diagnosis and treatment of bee diseases are very significant. Nowadays, mass deaths of bees in the form of colonies are occurring, and permanent solutions to these deaths are sought. The use of chemicals is not recommended due to their harmful effects. Especially, the use of antibiotics is prohibited because they cause residues in bee products and bees. However, it is a fact that beekeepers use them to prevent bee deaths. For this reason, scientific studies are being carried out to produce natural products and to find solutions to bee diseases with these products. For this reason, in this chapter, general definitions of bee diseases and chemicals and biological natural products used in bee diseases are explained.