About 1/3 of the patients suffering from epilepsy cannot be controlled with proper pharmaceutical treatment. Ketogenic diet is an effective treatment for such patients. In this study, we select thirty children aged 1-5 year-old, recognized as intractable epilepsy that fails to respond to drug treatment, who applied to Children’s Medical Center in Tehran, during the first six months of the year 2014. Those should be qualified for receiving ketogenic diet, and prescribe them, as outpatients, a kind of ready-made ketogenic diet, called Ketocal Powder for a period of four months. The Ketocal formula will constitute the major daily diet of the patients, and their carbohydrate-content food will be minimized. Blood sampling were done at the beginning and end of intervention for measurement of some parameters, In addition, The ketone content of their urine will be checked daily. Those who can not complete the formula consumption and/or in case of severe complications will be excluded . The patients’ formula tolerance, complications, the effect of the Ketocal formula on reduction of seizures will be assesed clinically and also by electroencephalogram twice during the period of study. If this kind of powder proves to be effective, then, it may be prescribed as a proper, ready-made and accessible diet to the patients suffering from intractable epilepsy, leading to reduction in hospitalization and decrease the burden of the illness.