This paper provides an informed and critical understanding of the concept of self-esteem. It explores this psychological construct in relation to its use in adventure education and outdoor learning. Enhancing a participant's self-esteem is perceived to be fundamentally a good thing and is culturally linked to the Hahnian notion that implies outdoor education is good for character-building and more recently personal development. This paper suggests that the improvement of self-esteem has become a reified programme outcome as well as an argument for the value and importance of outdoor education programmes. In this paper I seek to address the often uncritical and at times evangelical claim that outdoor programmes enhance self-esteem. This paper looks at the development of self-esteem generally and then considers its appearance in the outdoor education literature. Aspects of this that relate to outdoor learning and adventure education include: development of the self, behaviour, disaffected young people, recent UK developments and common misconceptions regarding self-esteem. These are explored and their implications for practice and research are considered. The essence of this paper is that outdoor educators need to be more critical, informed and specific about exactly what it is they are trying to achieve, how their programmes are evaluated, particularly with outcomes that are related to potential changes in "self" and how these changes are measured. (Contains 1 table, 1 figure and 6 notes.)