Urban residential neighbourhoods, including migrant neighbourhoods, have become important incubation zones for small businesses in recent years and policy-makers and academics alike are wondering which local factors affect this development. This paper analyses the extent to which migrant neighbourhood characteristics related to the built environment and the local regulations matter in determining the possibilities for small businesses. It contrasts two types of neighbourhood in the Netherlands—pre-war neighbourhoods with little functional separation between residential and commercial purposes, and post-war predominantly mono-functional residential neighbourhoods. Quantitative and qualitative methodologies are combined using available firm data from trade registers of the Dutch chambers of commerce, reviewing neighbourhood zoning regulations and conducting focus group and individual interviews with neighbourhood experts and entrepreneurs. It is found that the built and regulatory environment of migrant neighbourhoods does indeed appear to impact significantly on the chances of setting up a business and its subsequent fate.