Introduction: The ketogenic diet has been widely and  succesfully used for  the past 90 years as a therapeutic option in patients with drug resistant epilepsy. Its effectiveness , tolerability and side effects has been reported in a series of publications, nonetheless its outcome once suspended has been not.

Objective: to describe the effectiveness and safety of ketogenic diet and their outcome once their treatment was concluded. 

Material and methods. 82 medical charts from the ketogenic diet program of our Institution were reviewed.

Results: 10 patients achieved 100% seizures control, 20 achieved 90%, 30 managed to control between 50-90 % of seizures, 15 patients less than 50% of seizures and 7 patients had no response.
Regarding the outcome, 22 patients remain in diet so far, 26 were suspended (22 due to lack of response and 4 withdrawals because of side effects), 4 patients died and 30 patients concluded the 2 years period of treatment. From these 30 patients 12 increased seizures frequency, in 3 ketogenic diet was reinitiated with similar seizure control afterwards.

Conclusions. In our experience we report similar results from those published in terms of tolerability and efficacy of ketogenic diet. A high relapse rate was reported in those in which this treatment was suspended after the initial 2 years period, achieving acceptable seizure control once restarted.