Abstract Major natural catastrophes such as floods, fire, darkness, and ‘sky falling down’ are prominently reflected in traditional South American creation myths, cosmology, religion, and worldview. Cosmogonic myths represent a rich and largely untapped data set concerning the most dramatic natural events and processes experienced by cultural groups during the past several thousand years. Observational details regarding specific catastrophes are encoded in myth storylines, typically cast in terms of supernatural characters and actions. Not only are the myths amenable to scientific analysis, some sets of myths encode multiple catastrophes in meaningful relative chronological order. The present study considers 4259 myths, including 284 ‘universal’ (perceived in the narratives to be worldwide) catastrophe myths, from 20 cultural groups east of the Andes. These myths are examined in light of available geological, palaeoenvironmental, archaeological, and documentary evidence. Our analysis reveals three likely major Plinian volcanic eruptions in Columbia and the Gran Chaco. We also identify a set of traditions that are probably linked to the well-known Campo del Cielo iron meteorite impact in northern Argentina around 4000 years ago, along with a separate set of traditions alluding to a possible airburst in the Brazilian Highlands. These impacts apparantly triggered widespread mass fires. There are hints of cosmic impacts in the mythologies for other locations in South America.