1. Two years' experience with Mesantoin shows it to be a highly valuable anticonvulsant drug. It can be used alone in the control of grand mal, especially Jacksonian attacks. It may be of some benefit in psychomotor seizures.2. We have found that Mesantoin is best combined with dilantin sodium. Dilantin sodium is still perhaps the most effective anticonvulsant remedy and should be the base upon which other drugs are added.3. The dosage of Mesantoin and dilantin sodium must be individualized and adjusted to the need of the patient. May we impress the goal of a limited number of spells, not a reduced number of pills.4. A common effective dose for adults is dilantin sodium 1 to 3 capsules, and mesantoin, 4 to 6 tablets daily. This combination has proved more effective in controlling seizures than any previous single drug or combined drugs which we have used.5. Side actions of Mesantoin include drowsiness and skin rash. As a rule patients acquire tolerance to the drowsiness in a period of time. Dexedrine and physical activity tend to free the patients from the somnolence.6. Effective control of an epileptic requires close and continued observation and treatment.