This study investigated the perceptions of children with Attention-Deficit/Hyperactivity Disorder (ADHD) of their ADHD symptoms in terms of the positive illusory bias (PIB), their attributions for their problem behaviors, and their beliefs about whether their problem behaviors and disorder are stigmatizing. Participants were 152 9- to 14-year-old children (86 ADHD). Children with ADHD demonstrated a PIB for their ADHD symptoms; the discrepancy between their self-reports and parent reports was greater than for children without ADHD. They also viewed their self-identified most problematic behavior as more uncontrollable and stigmatizing (i.e., bothersome to others, leading to differential treatment, and embarrassing) than comparison children. Their perception that their problem behaviors and their disorder were stigmatizing was negatively associated with behavioral self-concept and self-esteem. These results suggest that school psychologists should interpret the self-reports of problem behaviors of children with ADHD with caution while being aware of the vulnerability of these children to feelings of stigma. (Contains 2 tables and 1 note.)