The aim of this essay is to better understand the role animal bones played in high- and late medieval societies (1200-1520), in modern-day Sweden. This is done by examining the contexts of bone depositions in two town areas of Nyköping and Enköping, as well as different uses of animal bones in medieval society. The use and deposition of animal bones are discussed in relation to the modern meaning of waste, and purity and impurity in pre-industrial societies. It was shown that the animal bones probably had a more complex role than what is conveyed by the word waste, but also that their role was not fixed but could change according to the circumstances.