This article looks at three Italian mafia organizations (Cosa Nostra, Camorra, and ‘Ndrangheta). It applies an organizational approach to the understanding of violence in mafia organizations by studying the relationship between their organizational orders and their criminal behavior. The article identifies two different organizational orders, vertical and horizontal, and demonstrates that Italian mafias, although operating in similar environments, can greatly differ from each other, and over time, in terms of their organizational model. Findings suggest that mafias with a vertical organizational order, due to the presence of higher levels of coordination, (1) have greater control over conflict, as proved by the lower number of “ordinary” murders; and (2) have greater capacity to fight state repression, as testified by the greater number of “high-profile” assassinations (e.g. politicians, magistrates, and other institutional members) that they carry out. Evidence is provided using a mixed-methods approach that combines a qualitative, organizational analysis of historical and judiciary sources, in order to reconstruct the organizational models and their evolution over time, with a quantitative analysis of assassination trends, in order to relate organizational orders to the use of violence.