Objectives: To investigate the presence of apathy symptoms in adolescents and adults with ADHD as a behavioral manifestation of underlying motivational deficits and to determine whether apathy symptoms were associated with a specific neuropsychological profile. Method: A total of 38 ADHD participants (28 of the combined subtype [ADHD/C] and 10 of the inattentive subtype [ADHD/I]) and 30 healthy controls (Ctrl) were assessed on two measures of apathy administered to subjects and informants. As well, ADHD participants completed a comprehensive neuropsychological battery. Results: ADHD participants presented elevated scores on measures of apathy relative to controls (ADHD/I greater than ADHD/C greater than Ctrl). Informant-based ratings of apathy correlated significantly with behavioral measures of inattention. Apathy measures correlated significantly with executive tests, working memory, verbal fluency, and general intellectual abilities, only in the inattentive sample. Conclusions: This study stresses the relevance of motivational deficits in adult ADHD as a significant clinical dimension closely linked to inattention and executive difficulties. (Contains 2 tables.)