Numerous studies have found evidence to support the presence of a positive illusory bias (PIB) in children with attention-deficit/hyperactivity disorder (ADHD; Diener & Milich, 1997; Hoza et al., 2004; Hoza, Pelham, Dobbs, Owens, & Pillow, 2002; Ohan & Johnston, 2002; Owens & Hoza, 2003). However, the underlying mechanism of the PIB has yet to be determined. Although a number of researchers have hypothesized that underlying executive functioning deficits in children with ADHD may be associated with a PIB (Hoza et al., 2001; Owens & Hoza, 2003), to date, no study has examined the relationship between executive functioning and the PIB in children with ADHD. Thus, the primary purpose of this study is to examine executive functioning as it relates to the PIB in children with ADHD. Participants included 34 children in the ADHD group and 30 children in the CTL group. Participants completed six tests of executive functioning including: a Stop Signal Task, the D-KEFS Color-Word Test, Digit Span, the Stanford-Binet Spatial Working Memory Test, the D-KEFS Tower Test, and the D-KEFS Sorting Test. Following each task, participants completed a task-specific self-evaluation estimate. Participants also completed a set of easy mazes and impossible mazes followed by posttask self-evaluation estimates. In conjunction with a parallel research project, the following measures were also obtained from participants: Self-Perception Profile for Children (SPPC), Teacher Rating Scale of Child's Actual Behavior, Wechsler Abbreviated Scale of Intelligence (WASI), Disruptive Behavior Disorder Rating Scale (DBD), Parent and Teacher Impairment Rating Scale (IRS), Children's Interview for Psychiatric Syndromes – Parent Version (P-ChIPS), and a demographic questionnaire. Consistent with previous studies, group differences in executive functioning and overestimations of competence were found. The ADHD group performed significantly worse than the CTL group on four of six measures of executive functioning, even after controlling for IQ. In support of the PIB, it was hypothesized that children with ADHD would overestimate their performance on executive functioning tasks significantly more than control children. This hypothesis was partially supported by analyses revealing that children with ADHD overestimated their performance more than controls on three of six task-specific self-perception discrepancy scores. Additionally, the relative contributions of depression, executive functioning performance and ADHD symptoms in the self-perceptions of participants were examined by using both traditional SPPC discrepancy scores as well as task-specific discrepancy scores. Results of the current study provide preliminary evidence that executive functioning may influence the self-perceptions of children with ADHD. Specifically, higher executive functioning was found to be related to lower overestimation of competence in one broad domain (e.g., SPPC Scholastic) and a number of task-specific domains.