The Carthaginians in the Library of Diodorus Siculus are often depicted as hostile barbarians. The author selects, combines and recycles ancient stereotypes about barbarians, like Phoenicians and Persians, in order to create new repulsive clichés of Carthaginians as enemies of all the Greeks, but the historical facts given by Diodorus enable the modern reader to use the Library as a quite reliable historical source even when he sets about the task of contradicting this anti-Carthaginian propaganda. The aim of Diodorus is to give a coherent view of the whole history of Sicily united by Greeks and then by Romans against the Barbarians embodied in the historical times by the Carthaginians. The posterity of these repulsive clichés of Carthaginians is very important until nowadays perceptions of this people even if the traditional pejorative judgement on Diodorus as being a mere compiler may have underestimated it.