This study evaluated the relationship of (a) reactive inhibition and right-lateralized emotion processing to each other and (b) to executive control of response suppression, and (c) with regard to ADHD in 134 children ages 7-12 years. Reactive inhibition was indexed by child ratings of sensation seeking on the Sensation Seeking Scales, executive control by the Stop Signal Task, emotion processing by performance on the Chimeric Faces Test, and ADHD by parent- and teacher-reported symptoms. The results were consistent with a two-process model in which executive control, conceived as a right-hemisphere lateralized function, was distinct from sensation seeking and lateralized emotion processing. Supporting this distinction, ADHD was associated with executive control, but not with sensation seeking/reactive inhibition or lateralized emotion processing. The findings suggest that ADHD cannot be understood as a global right-lateralized neuropsychological weakness, but rather that it involves only particular functions that may be right lateralized. Findings further suggest that risk for comorbid disorders in ADHD (e.g., conduct disorder or mood disorders) may increase as a function of independent factors such as temperament. Mechanisms underlying executive inhibition and emotional processing could be functionally independent yet interact to multiply psychopathological risk in some children (leading, for example, to comorbid disorders).