The goal of the new 5th edition of Ash & Orihel's Atlas of Human Parasitology is to provide the user with the most comprehensive and up-to-date source of information for parasite diagnosis in the laboratory. Increased world travel and large scale immigration are bringing zoonotic and other 'opportunistic' parasites to puzzle laboratory personnel in the developed world: the new Atlas of Human Parasitology, provides the crucial diagnostic information. In addition to new imaging throughout, new features have been added: quick morphologic keys, clinical images of infection, 12 entirely new plates, important diagnostic procedures, and expanded treatment of parasite-like artifacts and pseudoparasites culled from cases actually submitted to working diagnostic labs. In addition, the 5th edition includes thoughtful commentary on how newer modalities for molecular diagnosis work best in concert with morphology. Simply put: Ash & Orihel's Atlas of Human Parasitology, 5th edition is the essential microscope-side guide to parasite diagnosis for every clinical laboratory.