Parasitic infections and infestations are a major challenge to poultry production worldwide. This chapter comprehensively surveys parasites affecting poultry, divided into the broad categories of protozoa, flagellates and worms as well as arthropods including lice, bedbugs, flies, beetles, mites, fleas and ticks. The chapter examines diagnosis, control, management and disinfection for each of the major parasites associated with poultry farming. It also addresses the pathology, epidemiology and molecular biology of the major parasitic infections, and suggests lines of future research and enquiry in this field.