Limited research has been published about the demographic characteristics of children with Autism Spectrum Disorder (ASD) in South Africa. Describing the profiles of learners from a school for children with ASD may contribute to local knowledge in the field. A retrospective comparative design was utilised to compare the demographic characteristics of learners over two time intervals: 1992-2002 (Group 1, n=32) and 2003-2014 (Group 2, n=109). A total of 141 historical admission records in paper-based files were reviewed. Results indicated that there is a large male gender bias (8.4:1) in learners, which increased over the years. The age of the child when parents first became concerned and the age at diagnosis and assessment at school increased over both time periods. There was also an increase in the diversity of home languages after 2002. Parental qualifications decreased, but social class improved in recent years. The low qualification of a mother was associated with an advanced age of the child at school entry. The data serves as a point of reference for future studies about the characteristics of school children with ASD in South Africa.