This research attempts to explain the large differences in the early diffusion of the mafia across different areas of Sicily. We advance the hypothesis that, after the demise of Sicilian feudalism, the lack of publicly provided property-right protection from widespread banditry favored the development of a florid market for private protection and the emergence of a cartel of protection providers: the mafia. This would especially be the case in those areas (prevalently concentrated in the Western part of the island) characterized by the production and commercialization of sulphur and citrus fruits, Sicily’s most valuable export goods whose international demand was soaring at the time. We test this hypothesis combining data on the early incidence of mafia across Sicilian municipalities and on the distribution of sulphur reserves, land suitability for the cultivation of citrus fruits, distance from the main commercial ports, and a variety of other geographical controls. Our empirical findings provide support for the proposed hypothesis documenting, in particular, a significant impact of sulphur extraction, terrain ruggedness, and distance from Palermo’s port on mafia’s early diffusion.