This article aims to contribute to an overview of the situation of vulnerability and social exclusion of undocumented migrants crossing the Petén-Tabasco border in southern Mexico. Starting from the application and the many o little professionalization that the authorities have in respect of human rights. The objective of this paper is to locate the position of Social Work with vulnerable populations of undocumented migrants, this discipline comes on the scene when it is seen that there are no social workers in the different migratory units and in the migrant's house "la 72 "(At the border crossing with Tenosique). Therefore, the proposal is to integrate its principles and aims from the observation of the abuses and exclusions detected in the area towards migrants, and make recommendations for the purpose of improving the lives of these communities.