Although there is a debate about the importance of self-esteem in education, many primary teachers wish to help children who suffer from low self-esteem. However, in order to do this, we first have to identify such children. It is almost taken for granted that we can make quite accurate judgements based on the knowledge built up through day-to-day interactions with the children. This paper reports a small-scale study which looked at the match between teacher judgements of their pupils' self-esteem and the children's own self reports. The findings suggest we may not be as good at this as we would like to think. (Contains 1 note and 1 table.)