Objective: Children with ADHD have an increased risk of poor academic performance. It is important to identify cognitive processes that may be related to this academic failure. In Western schooling systems, especially language processing skills may be of relevance. The present study, therefore, compares the ability to comprehend complex sentences of individuals with and without ADHD. Method: Fifteen children (aged 8-11) and 15 adolescents (aged 12-16) with ADHD combined subtype are matched for age, gender, and parental level of education to 30 control subjects. Language comprehension is measured using the neuropsychological procedure proposed by Luria and an adapted version of the Token Test. Results: Compared with the control group, children and adolescents with ADHD perform significantly slower on language comprehension tasks. Differences in accuracy are limited. No interaction between age and ADHD is found. Conclusions: Children and adolescents with ADHD are slower and less efficient than matched control subjects with regard to complex sentence comprehension. (Contains 1 figure and 4 tables.)