Objective: To evaluate the performance of adults with ADHD considering the fractionation of executive functions into six different domains. Method: Participants were adult ADHD patients who were not under the acute effects of medication (n = 48). Their performance was compared with that of a healthy control group (n = 20) of comparable age, education, and nonverbal intelligence quotient. The cognitive domains assessed were executive shifting, updating, inhibition of prepotent responses, dual-task performance, planning, and access to long-term memory. We also assessed the symptoms of inattention, hyperactivity/impulsivity, anxiety, and depression by validated questionnaires. Results: Compared with controls, patients reported more symptoms related to ADHD, anxiety and depression symptoms and were impaired in the shifting cost measure and phonemic fluency (measure of access to long-term memory). Conclusion: ADHD in adults selectively impaired executive shifting and access to long-term memory, domains that may alter performance in a wide range of daily tasks.