Seventeen patients with intractable seizures have been treated with the medium-chain triglyceride (MCT) diet. All had frequent (often daily) seizures despite multiple medications. Age range was 12 months to 13 years. Types of seizures included myoclonic, akinetic, focal motor, atypical absence, generalized tonic, and tonic-clonic. Five patients achieved total seizure control, and anticonvulsants were decreased or stopped. Five others had some improvement in seizure control. No change was seen in two. In two cases, parents could not deal with the diet, even though total control had been achieved in one case. The diet had to be discontinued in three others because of side effects (diarrhea, vomiting, irritability). Intractable seizures of all types may respond to treatment with the MCT diet. This mode of therapy has few side effects, is tolerated well in most instances, and can result in reduction or discontinuation of anticonvulsant medications.