Multi-seater latrines, as we find them in Roman Ostia and in many other sites across the Mediterranean, are well known both to tourists and archaeologists, but very few people understand how they really functioned technically or how they may have been perceived in the context of Roman society. This handbook by an international group of specialists in archaeology, anthropology, and classical literature addresses a wide variety of questions regarding toilets in the Greco-Roman world. Chapters on the technology and construction of toilets, on the archaeology of toilets and their contents, on toilets in various ancient contexts (such as in private houses, baths, or military installations), on the impact of toilets on society and personal hygiene, especially in the Roman world, and on the decorations and graffiti from toilets, all combine to make this the most complete study of this important subject to date.