An immigration reception “house” which has the aim to deal with both first aid problems (food and bed) and health and social needs (medical and social services) involves many variables with a high level of interaction, hence a complex system. In order to manage such an infrastructure which can host a limited number of immigrants with different type of characteristics (Status – single(male/female), part of a family,…; Geographic provenience- Europe, Africa, Asia, …; Religion- Christian, Moslem, …; …) offering a selected number of services is not an easy job.On the base of a enlarged project sponsored by the department of social activities of Lazio Region (the region which includes Rome city) aiming to train and supply tools to a number of intercultural mediators a system dynamics model has been developed both to analyse and better understand the overall immigration reception process and to create a sort of “flight simulator” in order to evaluate, in advance, some decision effects over possible scenarios.The paper will describe both the structure of the model which has been developed to embed, as much as possible, the whole process and a set of results produced in reply of a set of what-if analysis.