About 10% of children become seizure-free after initiation of the ketogenic diet, and typically stop the diet after 2 yr. A retrospective chart review was performed of all children who became seizure-free on the ketogenic diet at our institution since 1993 and then discontinued the diet. Of 557 children started on the diet since 1993, 66 (12%) discontinued the diet after a median of 2.1 yr due to seizure freedom; 92% were also medication-free. Thirteen (20%) had recurrence of their seizures at a median of 2.4 yr (range: 0-5.5 yr) after the diet was stopped. Seven (58%) became seizure-free a second time, four with anticonvulsant therapy. Four patients (6%) continue to have daily seizures despite both medication and dietary therapies. The presence of recent EEG epileptiform activity, abnormal MRI, lower initial seizure frequency, and tuberous sclerosis complex all significantly increased the likelihood of recurrence.