This study addresses the issue of illusion of incompetence among elementary school children. The first objective is to examine whether teachers are able to recognize children with an illusion of incompetence. The second objective is to see whether teachers' appraisal of the behaviours and psychological characteristics of these children differ from their appraisals of other children. Seventy-four teachers and their 684 pupils from the fourth and fifth grades who were participating in a larger project were examined. By and large, only 31.3% of the pupils affected by an illusion of incompetence were identified as such by their teachers. However, teachers evaluated boys with an illusion of incompetence as being less autonomous, having a more negative mood and being more withdrawn than their peers. The teachers did not report these characteristics in girls with an illusion of incompetence. The discussion focuses on various hypotheses likely involved in teachers' difficulty in identifying children whose self-appraisals of competence are negative. (Contains 3 tables.)