Immigrants are frequently considered as carriers of unknown and/or exotic diseases. On the basis of data collected by a working unit of Palermo, specifically devoted to the immigrants, we may affirm that the more frequent medical problems (67.1%) were of internal origin (especially gastro-enterologic, rheumatologic and dermatologic) with an important psycho-somatic component. Infections were less common (20%) especially related to respiratory diseases. Other more dangerous infections, as Tbc and HIV related diseases, were rather infrequent (3%). As a whole, our data demonstrate that control and surveillance of migrants are necessary in order to avoid diffusion of pathologies among these (compromised) hosts. The risk of transfer of infections to residents is rather low.