This report brings together the findings of research projects about the nature, origins and consequences of variations in self-esteem among young people. It considers the potential role of self-esteem in intervention with vulnerable young people and examines the nature of self-esteem. It explores to what extent self-esteem is a quality that some individuals possess more of than others and whether it is a state that fluctuates. The report also highlights the difficulties in relation to measuring changes in self-esteem and how it can be modified through interventions. Most notably, this report outlines what is known about self-esteem and the consequences of high versus low self-esteem, recognising that high self-esteem does not necessarily have only positive outcomes.