Migrant workers show an increase in the incidence of serious, psychotic, anxiety, and post-traumatic disorders due to a series of socio-environmental variables, such as loss of social status, discrimination, and separations from the family. The purpose is to elaborate a systematic review and highlight the prevailing psychological pathologies of these workers and categories most at risk. Our research included articles published from 2009 to 2019 on the major databases (Pub Med, Cochrane Library, and Scopus) using a combination of some keywords. The online search indicated 1.228 references. Using inclusion and exclusion criteria, we analyzed 127 articles, in particular 12 reviews and 115 original articles. Principal emerging disorders from the research are depressive syndrome (poor concentration at work, feeling down, or anger and somatization), anxiety, alcohol or substance abuse, and poor sleep quality. This causes low life conditions, which is also due to marginalization from the social context and strenuous work; in fact, migrant workers may suffer verbal or physical abuse, and they are often employed in dangerous, unhealthy jobs. It is therefore essential to increase the role of occupational medicine and promote wellbeing for this vulnerable job category.