To evaluate the time estimation abilities of college students with ADHD on a novel, complex task that approximated academically oriented activities. Totally 20 college students with ADHD were compared to a sample of 20 non-ADHD students. Both groups completed a task, and scores were obtained for time to complete the task, errors made, prospective time estimate, confidence in estimate, and retrospective time estimate. In addition, scores were calculated for the difference between prospective estimate and actual time as well as the difference between retrospective estimate and actual time. Controlling for cognitive ability, the ADHD participants were significantly different from the non-ADHD participants on all dependent measures except confidence and errors. College students with ADHD showed retrospective time estimation difficulties that may be related to academic functioning in the college setting.