<title>Abstract</title> A retrospective study assessed the prevalence, timing, and distribution of psychiatric comorbidities in 322 Turkish children with ADHD (aged 6–18 years), focusing on potential sex differences. Data were collected from university-based clinical records. Assessments included periodic psychiatric examination, Wechsler Intelligence Scale for Children-Revised (WISC-R) and Conners’ Parent/Teacher Rating Scales (CP/TRS). Females with ADHD had higher psychiatric comorbidity rates compared to males (83.5% vs. 62.7%, p &lt; .001). Intellectual disabilities and speech disorders were more prevalent in females (p &lt; .001 and p = .028, respectively). Anxiety disorders were prevalent in both sexes. Higher rates of internalizing and externalizing disorders were observed in females. CTRS scores and indexes showed mild negative correlations with the timing of the first comorbidity other than neurodevelopmental disorders. Age and specific learning disorders (SLD) were predictors of comorbidity onset (p = .004 and p = .001, respectively). Females with ADHD need more clinical attention. ADHD severity, age, and SLD are important for the onset of comorbidities.