This study examines the tensions between the Global Statements of Ethical Principles of Social Work influenced by the Universal Declarations of Human Rights and related international conventions and the social work practices with undocumented immigrants in Sweden. The paper is based on a comprehensive study of working practices with undocumented immigrants in the framework of the Swedish social care system, where municipal social workers and non-governmental organisations (NGOs) actors have been interviewed. The material was complemented by participant observations. The empirical results show how globalisation, migration and social problems of undocumented immigrants increasingly challenge the national basis of social work and create tensions between national laws and practices guiding the Swedish welfare services and the Global Statements of Ethical Principles of Social Work. The lack of adequate working methods and legal frames makes it possible for social workers and NGO actors to make informal alliances with other actors for the improvement of undocumented immigrants’ living conditions. It is argued that the national basis of social work should be reformed in order to include global conditions of local social problems and realise itself as a human rights profession.