Distraction is a typical component of any classroom environment. For effective instruction and learning to take place, it is critical for students to eventually return to task and maintain task vigilance (i.e., returning to the task at hand) when a distraction occurs. Students with attention deficit hyperactivity disorder (ADHD), by definition, are more distractible than students without ADHD. However, studies showing specific variability of task vigilance between students with and without ADHD are limited. This correlational study examined the differences in distractibility on task vigilance between students with and without ADHD under conditions of distraction. Two groups of participants, ranging in age from 7 to 11 years, were identified. The participants with existing diagnoses of ADHD were matched to participants without ADHD by gender, age, grade, race, school performance, and ability to help maintain group equivalence. The procedure called for all students to complete simple math computations and copying tasks while exposed to a distracting stimulus. Results showed a marked, statistically significant difference in task completion rates for both tasks between groups. Secondly, students with ADHD had considerable difficulties disengaging from the distracting stimulus and returning to task (i.e., maintaining task vigilance). These findings, rather than generic deficits, may account for a large portion of underachievement suffered by students with ADHD. Treatment recommendations and implications for teaching students with ADHD are discussed.