[영문]The phenomenon of immigration has led to an important increase in the number of social programmes and services for migrant populations in many European countries. However, some investigations have shown that the use of formal resources is extremely low in these groups. In contrast to the limited utilization of programmes and services, research in the field of social psychology has revealed that the primary source of help and support for immigrants is their own informal social network. After analysing the characteristics, advantages and limitations of formal and informal support systems, this paper presents a typology of social support interventions with migrant populations that integrates both types of support. Four levels are differentiated: dyadic interventions, social network interventions, mutual aid groups and community interventions. The development of programmes to strengthen the informal support system is emphasized as an alternative to integrating formal and informal resources in social work practice with migrant populations.