This paper examines the meat supply system in Rio de Janeiro from the late nineteenth century to the 1920s. For a period of time the city's monopoly over meat processing and retailing guaranteed a steady supply at predictable prices. However, at the turn of the century, ‘interlopers’, as municipal officials labelled those who attempted to introduce their product into Rio's market, began to question this century-old monopoly. Hence, for a relatively short period, Rio de Janeiro implemented a number of measures: curtailing the long-standing custom of clandestine slaughtering; establishing a centralised and somewhat regulated public abattoir system; and, finally, introducing meat-packing companies. This study considers these developments by undertaking a broader inquiry into how they affected per capita meat availability in Rio de Janeiro from the 1890s to the 1920s.