There is a significant variability in the prevalence of psychotropic medication use among young autistic persons worldwide and this is under-studied in Australia. Apart from risperidone, approved by the Therapeutic Goods Administration to manage challenging behaviour, the appropriateness of other psychotropic medications prescribed to young autistic persons warrants scrutiny. This retrospective study aims to gain initial insight into the magnitude, types and indications of psychotropic medication use in autistic children and adolescents in Western Australia. We analysed de-identified data from 239 autistic children and adolescents ([less than or equal to] 21 years) who participated in the Western Australian Autism Biological Registry between 2011 and 2015 and who completed a questionnaire regarding medication use. One-quarter (n = 66, 28%) of young autistic people reported using a total of 137 medications. Most (n = 46, 70%) of those medicated were under 12 years of age; half (n = 33) were 6-12 years and a fifth (n = 13) were under 6 years. The most used medications were stimulants (n = 35, 53.0%), followed by antidepressants (n = 24, 36.4%), antiepileptics (n = 21, 31.8%), sedatives (n = 15, 22.7%) and antipsychotics (n = 14, 21.2%). These medications were mainly to manage attention deficit hyperactivity disorder, challenging behaviours, seizures, insomnia, undefined anxiety, depression and mood instability. While most autistic young people in the Western Australian Autism Biological Registry did not report using psychotropic medication, over a quarter were prescribed medications, primarily stimulants, to manage symptoms of attention deficit hyperactivity disorder. Various medications, including risperidone, were used to help manage challenging behaviours. Medication use should be studied more comprehensively in a larger cohort of autistic persons to confirm our current preliminary observations. Further, future studies should monitor the effectiveness and safety outcomes of such medications due to a limited understanding of their effectiveness in managing the atypical presentation of co-occurring disorders in young autistic persons.