Purpose <p>This study aimed to examine the mediating role of cognitive disengagement syndrome (CDS) in explaining social communication difficulties in children diagnosed with Autism Spectrum Disorder (ASDLevel 1).</p> Methods <p>The sample included 107 children (58 with ASD-Level 1 and 49 typically developing controls). Autism symptom severity (ASSQ), cognitive disengagement (CABI-SCT), social communication (SCQ), and daytime sleepiness (ESS-CHAD) were assessed. Group comparisons, correlation, regression, and mediation analyses were conducted.</p> Results <p>Compared to controls, the ASD-Level 1 group had significantly higher scores on ASSQ, CABI-SCT, and SCQ (<i>p</i> &lt; .001). Regression analysis showed that both ASSQ (β = 0.382) and CABI-SCT (β = 0.124) significantly predicted SCQ scores, while Epworth had no effect. Mediation analysis indicated that CDS partially mediated the relationship between ASSQ and SCQ (indirect effect = 0.099, 95% CI [0.041, 0.181]).</p> Conclusion <p>Findings suggest that social communication deficits in ASDLevel 1 are not solely explained by core autism symptoms. CDS may independently and transdiagnostically contribute to social dysfunction and should be considered in clinical evaluations and interventions. The study emphasizes the need to move beyond core diagnostic criteria and incorporate cognitive disengagement processes into clinical models of autism. CDS may represent a novel, modifiable target for intervention in ASD-Level 1 populations with preserved cognitive capacity but impaired social functioning.</p>