Refractory childhood epilepsy refers to those cases with difficult control of epileptic attacks after at least two formal anticonvulsants treatment. Recently, ketogenic diet (KD), a high-fat, low-carbohydrate and adequate-protein diet, becomes an important method for the treatment of refractory epilepsy in children. Before employing KD, children should be checked to exclude known metabolic diseases. Although the mechanism of KD treatment is not entirely clear, it has a certain clinical curative effect. Many factors influence the curative effect of KD. Most of the adverse effects of KD treatment are transient and can be recovered through active prevention and handling, which gives a generally good prognosis.