Introduction: Rapid automatized naming (RAN) is the ability to name, as fast as possible, symbols such as letters, digits and figures. The present study aimed to investigate intragroup performance patterns on RAN tasks in children with attention deficit hyperactivity disorder (ADHD) symptoms alone, children with reading disability (RD) alone and controls with typical development. Methods: A total of 216 Brazilian children between 8 to 11 years old were selected from public schools located in two Brazilian capitals, namely Porto Alegre and Belo Horizonte, to participate in the study. Mixed 3 (participant group: ADHD symptoms, RD or control group) × 3 (type of stimulus: letters, numbers or figures) ANOVAs were performed using response time and number of errors as dependent variables. Only intragroup comparisons are described in this paper. Results: The groups with ADHD symptoms and RD showed similar performance results on naming speed. There were no differences between letters and numbers within each group, but we found slower responses in figure naming compared to the other tasks for both groups. Concerning accuracy, children with ADHD symptoms showed a similar number of errors in all three tasks. These patterns were distinct from the performance of the control group. Conclusion: Results suggest a shared deficit in naming speed of alphanumeric stimuli in children with ADHD symptoms and those with RD, and impairments in naming digits correctly in children with ADHD symptoms.