There are a number of transitions and crises periods in the life span of every individual and adolescence represents one of these periods where great strain and sometimes confusion results. In the Winneba municipality in Ghana for instance, it has been noted that majority of the students in the senior high schools, come from different regions who attend school in this municipality. As a result, it has been noted that they spend most of their time with their peers than with their parents; since they are resident students. In view of that it is assumed their peers have great influence on their behaviours. It is upon this note that the researcher would like to investigate into peer support mediating adolescents' psychosocial problems and their self-concept. This analysis should help counsellors to be aware of the prevailing psychosocial problems of adolescents in the municipality and thereby find ways of improving their services to assist them in their schools. It should help create the awareness of parents, teachers and guidance and counselling coordinators about the extent to which the peer group influence the adolescents' self-concept and also the need to develop the self-concept.