Methysergide (1-methyl-lysergic acid butanolamide) was used experimentally in 78 patients with psychomotor epilepsy and with focal abnormal activity (sharp waves) in one of the temporal lobes, in the EEG. The usual dosage of methysergide was 2 to 6 mg daily (only 36 patients received more than 2 mg daily) and every patient received fenobarbital 0.1 g daily also. Out of the 78 patients, 59 responded well to the treatment; 47 were free of seizures and in 12 there was decrease in frequency and severity of seizures. Psychic symptoms also decreased with the use of methysergide. The EEG was improved in 27 per cent of patients and became normal in 37 per cent, after twelve months of treatment. Slight side effects were reported by 39 pacients but they disappeared in a few days.