Human sacrifice was practiced to some extent by many peoples in Mesoamerica (and for that matter, around the world) for many centuries. But it was the Aztec empire that really took the ritual to new heights. How many people were sacrificed by the Aztecs? We don't know how many were sacrificed over the years - it's possible that some accounts are exaggerated - but it was probably thousands each year - tens of thousands or more all together. Some estimates claim 20,000 a year.