<p>A majority of children with autism is diagnosed with one or more co-occurring mental health conditions. We aimed to explore how co-occurring conditions and Quality of Life differ between school types (general education vs. special education schools), and whether co-occurring conditions were subject to the same trends over time for the two school types. Secondary, we aimed to analyze associations with child characteristics. Repeated cross- sectional data from 2013 to 2022 on children with autism (N = 1534,aged 5–15 years) in the Netherlands were used. Across school types, we showed a decrease in externalizing and language-learning conditions over time. Language-learning conditions became more concentrated in special education schools. Hyperactivity-inattention difficulties remained stable, emotional difficulties decreased and behavioral difficulties increased. Compared to those in general education, children in special education schools faced more behavioral and hyperactivity-inattention challenges. School type, duration of the study, externalizing, internalizing and language-learning conditions were all unrelated to QoL. Autistic girls experienced more behavioral difficulties compared to boys with autism. In conclusion, children with autism in special education schools experience similar QoL, but have more (severe) co-occurring conditions than those attending general education.</p>