This study examines the changes that occur in multidimensional self-concept of adolescents with a diagnosis of intellectual disabilities, across gender and category of intellectual disability (borderline, mild, moderate) groups. A sample of 54 young people completed the Harter Self-Perception Profile. Using a three-wave longitudinal study conducted during their first year in a segregated special second-level school, stability and change in multiple domains of self-perception were examined. Findings indicate that gender and level of cognitive function are important variables in changes in self-perception across time, highlighting the heterogeneous nature of the special school population.