AbstractInfanticide is the killing of infants by conspecifics, and may be direct or indirect; and parental or non‐parental. Explanations for such behaviours range from forcing females with young back into heat, resource recycling in times of shortage and elimination of competitors. Though moderately well understood in some mammal groups, reports of infanticide in hystricomorph rodents are often contradictory and invariably based on captive observations, raising questions about the naturality of the behaviour and the conclusions derived from them. Here, we report the first wild observation of direct infanticide and cannibalism of two juvenile Azara's Agoutis Dasyptocta azarae by a group of adults in Paraguay, confirming that such behaviours also occur under natural conditions.