The relationship between Industrial Districts (IDs) and immigration has been studied so far through cases of ethnic economies developed within IDs by immigrant entrepreneurs. In this study we argue that there is a more general and complex interaction between the two phenomena that can give rise to the development of ethnic economies, either to the emergence of migratory enclaves (concentration of people migrated with the same nationality) depending on the degree of formality of the ID and local conditions of immigrant groups. Through the case study of ID ceramic Castellón we suggest that the interaction between the formal job offer characteristic of the ceramic sector and the existence of a support network initiated by the Adventist church, allowed the population of Romanian origin to have initial conditions comparatively favorable in relation to other immigrant groups, representing 12% of the total population of the province in 2012. Design / Methodology: This is a descriptive and exploratory work based on the participant observation carried out between the months of February to July 2016. The activities of the ethnographic observation have been complemented by statistical documentation and interviews open to representatives of Churches, associations charities, local authorities, the Romanian consulate in Castellón, companies targeting the Romanian population (mobile telephony and transport services), businessmen and experts in the ceramic sector of Castellón. Contributions and Results: Taking as an example the ceramic ID of Castellón, we show how this ID contributes to the creation of the conditions that favor an exceptional Romanian migratory enclave, both due to its demographic importance and the absence of conflict or significant tensions. We propose that the formal employment offer of the ID, although minority in relation to the total employment typically occupied by emigrants, had a positive effect on the decisions of sedentarization of this population. Originality / Value: This is a study that combines different disciplines such as economics and anthropology to offer a far-known vision of the effects of ceramic ID in immigration. Finally, a preliminary general model of interaction between ID and immigration is proposed.