Objectives: To assess the recurrence rate of epilepsy attributable to discontinuation of treatment in seizure free patients and to identify the risk factors for recurrence. Methods: 330 patients referred to an epilepsy centre who were seizure free for at least 2 years while on stable monotherapy were the study population. Discontinuation of antiepileptic drugs (AEDs) was proposed to all eligible patients or to their carers after discussion of the risks and benefits. Depending on whether they accepted or refused treatment withdrawal, the patients were stratified into two cohorts and followed up until seizure relapse or 31 March 1999, whichever came first. For each patient, records were taken of the main demographic and clinical variables. Results: The sample comprised 225 patients who entered the discontinuation programme and 105 who decided to continue treatment. Twenty nine patients (28%) continuing treatment had a relapse, compared with 113 (50%) of those entering the withdrawal programme. For patients continuing treatment, the probability of remission was 95% at 6 months, 91% at 12 months, 82% at 24 months, 80% at 36 months, and 68% at 60 months. The corresponding values for patients discontinuing treatment were 88%, 74%, 57%, 51%, and 48%. After adjusting for the principal prognostic factors, in patients discontinuing AEDs the risk of seizure relapse was 2.9 times that of patients continuing treatment. A relation was also found between relapse and duration of active disease, number of years of remission while on treatment, and abnormal psychiatric findings. Conclusions: Seizure free referral patients on stable monotherapy who elect to withdraw drug treatment are at higher risk of seizure relapse compared with patients continuing treatment. Severity of disease and seizure free period are significant prognostic factors. I n patients with epilepsy who are seizure free for a period while on antiepileptic drugs (AEDs), the question arises whether treatment can be withdrawn. The decision to discontinue AEDs is based on the chance of remaining seizure free after drug withdrawal, the presence of factors predictive of a higher risk of seizure recurrence, and the medical and social consequences of the withdrawal compared with continuation of treatment. The risk of seizure relapse after withdrawal of AEDs has been estimated at from 10% to 70% depending on the method and design of the studies. Based on a meta-analysis of the literature, 1 the risk of relapse after drug withdrawal was 25% at 1 year and 29% at 2 years. Several factors have been implicated in the risk of relapse, including age at onset of seizures, 2-7 age at treatment withdrawal, The risk of seizure relapse attributable to drug discontinuation is less well defined. The only study comparing continued antiepileptic treatment and drug withdrawal showed that 78% of patients continuing and 59% of those stopping AEDs remained seizure free two years after randomisation. 11 In that study the patients were enrolled regardless of whether they were taking one or mor...