Gambling has been Macau’s principal industry and a major source of income for the city for nearly 180 years. However, surprisingly little has been said about its urban impact and connections to a wider economy of vice, e.g. opium, pawnbroking and prostitution, which was consolidated in the second half of the nineteenth century mostly by the hands of a Chinese entrepreneurial elite. This article takes a novel approach to examining Macau’s early colonial development by historicizing the city’s modern economy from a different, mostly neglected urban angle. It shows that the development of vice businesses promoted the diversification of commercial activity, real estate development and the creation of public facilities, defining a type of ordinary urbanization, business-led rather than government-oriented, that affected Macau’s urban character and identity in durable ways.