Interspecific killing among mammalian carnivores is a common phenomenon, accounting for up to 60% of known mortalities in some species. These interactions can be symmetrical or asymmetrical, with adults of one species killing young but not adults of the other. There is a significant positive relationship between the body masses of solitary killer species and their victim species, and grouping species kill larger victims than solitary species. Interactions and consumption of victims are more common when food is scarce or disputed. Victims may alter their space use, activity patterns, and form groups in response to killers. Consequences of interspecific killing include population reduction or extinction, and changes in prey populations, which have important implications for conservation and management of carnivores and their prey. The study documents 97 different pairwise interactions involving 54 victim and 27 killer species, with canids, mustelids, and felids being the most involved families. The consumption of victims by killers is also documented, and the availability of alternative prey may influence interspecific killing and consumption. Direct effects of interspecific killing on victim populations can be high, ranging from 43% to 68% of mortalities, and can lead to population reduction or even extinction. Indirect effects include shifts in space use, temporal segregation, and group formation by victims. Conservation implications highlight the need to protect larger carnivores to control less desirable species and maintain prey populations. Further research is needed to understand the ecological and behavioral factors affecting interspecific killing in mammalian carnivores.Interspecific killing among mammalian carnivores is a common phenomenon, accounting for up to 60% of known mortalities in some species. These interactions can be symmetrical or asymmetrical, with adults of one species killing young but not adults of the other. There is a significant positive relationship between the body masses of solitary killer species and their victim species, and grouping species kill larger victims than solitary species. Interactions and consumption of victims are more common when food is scarce or disputed. Victims may alter their space use, activity patterns, and form groups in response to killers. Consequences of interspecific killing include population reduction or extinction, and changes in prey populations, which have important implications for conservation and management of carnivores and their prey. The study documents 97 different pairwise interactions involving 54 victim and 27 killer species, with canids, mustelids, and felids being the most involved families. The consumption of victims by killers is also documented, and the availability of alternative prey may influence interspecific killing and consumption. Direct effects of interspecific killing on victim populations can be high, ranging from 43% to 68% of mortalities, and can lead to population reduction or even extinction. Indirect effects include shifts in space use, temporal segregation, and group formation by victims. Conservation implications highlight the need to protect larger carnivores to control less desirable species and maintain prey populations. Further research is needed to understand the ecological and behavioral factors affecting interspecific killing in mammalian carnivores.