Underachievement has long been recognised as a problem for some gifted children. In such cases, the potential of these children may be a loss to society. Indeed, it has been argued that these individuals not only turn out to be relatively non-productive members of adult society but also they have potential personal problems. In spite of its importance there has been little research into underachieving gifted children since the seminal studies of Whitmore (1980). The aim of this research was to investigate the affective characteristics of achieving and underachieving intellectually gifted children. In particular, the three affective characteristics were academic self-concept, self-expectations for future achievement and academic locus of control for children who were moving from elementary school to a middle school setting. Forty- one participants were chosen who had a full WISC-R test over 125 from a large sample of middle school-aged children. Of these 41 intellectually gifted participants, 7 were classified into an underachieving group as a result of their scores on a Performance Achievement Test. The remaining 34 were classified into an achieving gifted group. A third group, classified as average achievers, was composed of students who had average WISC-R FS IQs and whose achievement test scores ... [more]were also average. Three constructs - academic self-concept, self-expectations of future academic achievement and academic locus of control - were measured on two occasions for the three groups, to assess if there were changes after the students had entered the middle school setting. The results indicated that the most discriminating construct between the groups was self-expectations for future achievement. The discussion focuses on appropriate remediation and on how newer areas of motivation, self-regulation and goal orientations may be more appropriate constructs to discriminate this group of learners.