A growing body of literature suggests that ADHD is associated with emotion recognition impairments that may be linked to deficient interpersonal functioning. However, our understanding of the mechanisms underlying these recognition impairments is extremely limited. Here, we used dynamic stimuli to investigate whether impaired emotion recognition in children with ADHD may be associated with impairments in perceptual sensitivity. Participants (ADHD: N = 26; Controls: N = 26) viewed video sequences of neutral faces slowly developing into one of the six basic emotional expressions (angry, happy, fearful, sad, disgusted and surprised) and were instructed to indicate via a button press the precise moment at which they were able to correctly recognize the emotional expression. The results showed that compared to controls, children with ADHD exhibited lower accuracy rates across all emotional expressions while there was no evidence for impaired perceptual sensitivity. Thus, the study provides evidence for a generalized categorization impairment across all emotional categories and is consistent with developmental delay accounts of ADHD. Future studies are needed in order to further investigate the developmental course of social cognition deficits in ADHD.