Mites are among the most important arthropods in greenhouses, both as pests causing economic injury to greenhouse crops and natural enemies used in the biological control of pest insects and mites in greenhouses. Because of their minute size, mites are much less well known than insects. Although a great deal has been written on mites of greenhouses in widely dispersed scientific literature, there is a lack of a comprehensive treatment dedicated to greenhouse mites. The need for such a book on the identification, biology and control of greenhouse mites has been brought to my attention by students, entomologists, pest control workers, and growers, indirectly through correspondence and directly through interactions with them in training courses and collaborative research. Control studies included the evaluation of field efficacies of seven pesticides against different stages. Mites pose a serious problem to plants worldwide, attacking crops and spreading disease. When mites damage crops of economic importance the impacts can be felt globally. Mites are among the most diverse and successful of invertebrates, with over 45,000 described species, with many more thousands to be discovered. They are responsible for a significant portion of the losses of crops for food, fiber, industry and other purposes, and require expensive and often controversial pest control measures.