To document the long-term evolution of juvenile myoclonic epilepsy (JME) in a population-based cohort.All patients developing JME by 16 years of age in Nova Scotia between 1977 and 1985 were contacted in 2006-2008.Twenty-four patients (17 women) had JME, 3.5% of all childhood-onset epilepsy. Age at first seizure was 10.4 +/- 4.3 years. We contacted 23 of 24 (96%) at a mean age of 36 +/- 4.8 years. All were initially treated with antiepileptic drugs (AEDs). At the end of a 25.8 +/- 2.4-year follow-up, 11 (48%) had discontinued treatment: 6 were seizure-free (without AEDs for 5-23 years), 3 had myoclonic seizures only (without AEDs for >18 years), and 2 continued with rare seizures. Convulsive status epilepticus occurred in 8 (36%) and 3 had intractable epilepsy. About 70% reported good satisfaction with their health, work, friendships, and social life (Likert scales). Despite 87% high school graduation, 31% were unemployed. Sixteen live with a partner, 7 alone. Nine received antidepressant medications. Ten women had > or =1 pregnancy and 4 men fathered a child. Eleven pregnancies (80%) were unplanned, outside of a stable relationship. At least 1 major unfavorable social outcome was noted in 76%.Our sample size is modest but the long follow-up and population-based sampling is unique. All seizure types in juvenile myoclonic epilepsy (JME) resolved in 17% and for 13%, only myoclonus persisted. Therefore, one-third of people with JME have troublesome seizures vanish and antiepileptic drug treatment is no longer needed. Depression, social isolation, unemployment, and social impulsiveness complicate the lives of many patients.