As a group, patients with epilepsy have reduced neuropsychological functioning and health-related quality of life (HRQOL), but the status of these factors is uncertain in seizure-free patients with seizure onset in adulthood on monotherapy. Nevertheless, some of these patients report neuropsychological problems. We hypothesized that subtle impairments in neuropsychological functioning and HRQOL may be underdiagnosed and related to these problems. Sixteen patients with localization-related epilepsy on monotherapy carbamazepine were compared with 16 age-, gender-, and education-matched healthy controls by means of a standardized neuropsychological screening battery, questionnaires about HRQOL (Short-Form Health Survey, SF-36), self-perceived neuropsychological functioning (Cognitive Failure Questionnaire), and mood (Profile of Mood States). No objective impairments in selective attention, memory, and executive functioning were found. However, a lower speed of information processing affecting everyday life functioning was found. Lower levels of self-perceived neuropsychological functioning were reported, whereas HRQOL was unimpaired relative to healthy controls. Physicians should not be reassured when patients receive adequate medication that prevents seizures; careful follow-up of speed of information processing and self-perceived neuropsychological functioning is needed.