Only recently have studies included a female Attention Deficit Hyperactivity Disorder (ADHD) sample when investigating neurocognitive functioning of individuals with ADHD. As such, the generalisability of findings of impaired executive functioning is limited to ADHD males. This study compared four groups aged 13-17 years: 30 male controls, 35 female controls, 24 males with ADHD, and 25 females with ADHD. Participants were assessed using the K-SADS-PL and Conners' Rating Scales, and completed tests of rapid naming, processing speed, memory, inhibition, set-shifting, and interference. Results showed that the males with ADHD and the females with ADHD performed similarly with only one notable difference: males with ADHD showed some evidence of more impaired inhibition than females with ADHD. In contrast, after controlling for reading ability, comorbidity, and IQ, both males and females with ADHD showed some impairment in working memory, naming speeds, processing abilities, and inhibitory deficits as compared with controls. This study supports the growing literature documenting impaired neurocognitive functioning in both males and females with ADHD.