We compared serial EEGs performed at admission, discharge, and follow-up (mean, 25 months) to clinical outcome in 70 patients with intractable epilepsy. The diagnosis in each case was confirmed by intensive monitoring. EEG features evaluated were background slowing, focal slowing, and focal, bilateral, or generalized epileptiform discharges. Clinical measures were seizure frequency and medication toxicity. No statistically significant correlations were found between improvement in any EEG feature and any clinical measure. EEG did not predict which patients would benefit from intensive monitoring. Serial EEGs may be of little value in assessing the results of treatment in patients with severe epilepsy.