Although some Latino communities see street food vending as part of their community traditions, most local governments tend to see it as a hazard to economic stability and public safety, and therefore attempt to restrict it through administrative regulations and criminal laws. This thesis explores the connections between immigrants, informality, and local policies through an ethnographic case study of street mobile food vending, a growing and often overlooked sector of immigrant economies in urban areas. It presents the role street food vendors play in U.S. urban life and the realities of their struggles as part of the informal economy. It then tackles the provocative question of why immigrants continue to sell informally despite restrictive vending laws through a literature review exploring the relationship between immigrants and the informal economy. The subsequent chapters examine a case study in the City Heights community in San Diego to determine whether restrictive food vending policies create higher rates of informality and to evaluate the consequences of the implementation of these on the health of immigrant vendors. Drawing on government documents, meetings with policy experts, and fieldwork with immigrant street vendors, I find that the complexity, costs, and restrictive nature of street vending policies are important factors in pushing immigrant vendors into informality. I also find that immigrant street vendors face a series of occupational health and safety hazards, some of which are exacerbated, if not produced, by the policy enforcement of restrictive vending laws. I conclude by proposing a set of realistic policy changes to San Diego's current street food vending laws.