The psycho-social problems of a group of 365 Italian emigrants to Switzerland, admitted to psychiatric hospitals, were studied. It was found that non professional subjects (housewives, unemployed, retired) and manual workers (builders, waiters, factory workers) were more likely to suffer from psycho-social disorders. Only 11.1% of those studied had received a secondary education, therefore it could be assumed that subjects having a low technical and cultural level were less prepared, psychologically, for their new situation and were thus more susceptible to psycho-social disorders. The most frequent diagnoses were found to be: affective disorders, alcohol addiction, opiate addiction and schizophrenia. The study revealed that emigrants ran a greater risk of first time admittance to psychiatric wards whereas the local population had a greater number of relapses. In conclusion it is stressed that assistance with an aim to improve work, social and relationship conditions and to integrate the emigrants into their host society can reduce some forms of psycho-social disorders.