Social exclusion is a wider concept than poverty and includes not only material conditions but also inability to participate in economic, social, political and cultural life. The essence of social exclusion is social relationships (more exactly breaking off relationships), which may mean not only pushing away some members of the society, but also breaking off relationships with the society from the side of a person himself/herself. The reasons of origin of social exclusion may be legal, political, economical, social and cultural. Nowadays social exclusion is predetermined by social-economic factors. According to Poviliūnas (2001), the problems of children’s social exclusion may be solved ensuring proper education, care of public health, safety and minimal life standard. Growing aggression and violence of schoolchildren and their social exclusion are nowadays an important issue of political debate and media reports. Often schoolchildren face the risk of social exclusion at school during the period of adolescence. The risk also depends on the social status of their family in the society and the relationship of the family members.The aim of the article is to identify characteristic features of schoolchildren at risk of social exclusion and analyze social support provided for them. A quantitative research was carried out to achieve the aim. The method of data collection is a questionnaire. 105 teachers working in 3 secondary schools in Lithuania participated in the research.The research results revealed that most often schoolchildren face the risk of social exclusion at school during adolescence period. They are characterized as incommunicative, unsociable, passive, and shy, do not trust others, are vulnerable, have learning problems and avoid collaborative activities. These schoolchildren usually come from families of social risk or single parent families. The support provided at school by teachers to schoolchildren at risk of social exclusion is only fragmentary. Further development of social skills and close cooperation of professionals working at school is necessary to prevent social exclusion.