Low glycemic index treatment (LGIT) is a newly developed dietary therapeutic option for epilepsy that is less restrictive than the ketogenic diet (KD). Our objective was to determine the efficacy and tolerability of LGIT.From March 2014 to February 2015, 36 patients received LGIT at Severance Children's Hospital. One-year seizure outcomes and side effects were evaluated.A total of 36 patients were assessed. Fourteen were female. Common diagnoses were Lennox-Gastaut syndrome (33%, 12/36) and Dravet syndrome (14%, 5/36). The median age at the initiation of the LGIT was 12.6years (min.=1.5, max.=28, interquartile range (IQR) 8-17). After 3months of therapy, 20 (56%) patients experienced a 50% or greater reduction in seizure frequency, which was maintained in 19 (53%) patients for 1year. Two (6%) patients became seizure-free after 3months of LGIT; they remained seizure-free for 1year. These two had Dravet syndrome and generalized epilepsy. Only three (8%) patients discontinued treatment within 1year. Adverse events were rare, and two patients (6%) reported transient diarrhea.LGIT effectively reduced seizure frequency in the present study, although seizure freedom was infrequently achieved. LGIT may be considered as a therapeutic option for patients with drug-resistant epilepsy, particularly those who find KD effective but intolerable.