The high number of dead bodies to deal with in time of mortality crises (events marked by an unusually high number of dead in a limited amount of time) often leads to modifications in the traditional funerary practices of a society. This contribution questions the way Ancient Greeks, from the 8 th till the 3 rd c. BC, handled such mortality crises, focusing on mass burials. In a first methodological part, we discuss the means to identify funerary sites related to mortality crises, using the methods of archaeothanatology. By confronting archaeological features (taphonomic processes, position of the remains, grave type, offerings, etc.) and bioanthropological data (number of dead, sex, age, pathologies, etc.), we will first define the main characteristics of mass burials. We will then question how to discriminate between mass burials linked to war, epidemics, massacres and famine, underlining the major importance of historical sources in this process. The second part is dedicated to the study of various cases from Athens, Paros, Chaeronea, Tanagra and Greek Sicily and their interpretation. We will argue that epidemic mass burials are the most difficult to identify, since they may present innumerable variations in terms of osteoprofiles and archaeological features. Finally, we will question our abilities, as archaeoanthropologists, to evaluate the impact of epidemics on the funerary treatment of the dead in the Ancient world.