The vast number of comorbid disorders associated with Attention Deficit Hyperactivity Disorder (ADHD) sheds a light over the need to reconsider the assessment protocols of children with this diagnosis, in what comorbid neuropsychological disorders, and language difficulties are concerned. This investigation aimed to assess ADHDs impact on language, on the phonological processing and comprehension domains, using the portuguese version of the Psycholinguistic Assessments of Language Processing in Aphasia (PALPA-P). Its usefulness in clinical practice and discriminative power were also assessed. Thirty-seven ADHD children were compared to 67 children from a control group, in terms of their performance in selected PALPA-P subtests. The results suggest that ADHD children show greater deficits in language tasks, particularly on phonological processing and comprehension tasks. This is a pioneer study in Portugal, on ADHD children assessment, using the PALPA-P test battery. The results show the test batterys clinical value, as well as its discriminative power, for the comprehensive assessment of these children.