Little is known about the medical decision-making abilities of older adults with chronic partial epilepsy, although these patients are often faced with medical decisions that impact their health care. Twenty-one older adults with epilepsy and 21 healthy older adults completed the Capacity to Consent to Treatment Instrument (CCTI) and Dementia Rating Scale II (DRS-II). Older adults with epilepsy performed significantly below controls on the CCTI standards Evidencing Choice, Appreciation, and Understanding and the DRS-II Total Score. DRS-II was positively associated with performance on the standards Appreciation and Understanding. Number of antiepileptic drugs, duration of epilepsy, and age at seizure onset were related to performance on Understanding. Older adults with epilepsy demonstrated deficits in their capacity to give informed consent for medical treatment that appear to be associated with cognition and seizure variables. Physicians should consider the decisional abilities of their older adult patients with epilepsy when presenting treatment options. © 2006 Elsevier Inc. All rights reserved.