This paper discusses the difficulties researchers are likely to encounter when assessing the self-concept of children with Down syndrome. It describes four potentially appropriate assessment methods: projective techniques, nonverbal and/or pictorial techniques, construct generation techniques, and topological techniques. The paper concludes that methods based on the Pictorial Scale of Perceived Competence and Social Acceptance (Harter & Pike, 1984) and personal construct psychology offer the most appropriate means for assessing the self-concept of children with Down syndrome.