A multicenter prospective study was initiated at the time of first antiepileptic treatment for afebrile seizures with 283 unselected patients in Italy. Each patient started with monotherapy at standard daily doses. Data were collected at admission, at scheduled 6-month exams, and at unscheduled exams and included age, sex, general profile of the disease, and treatment. Prognosis of epilepsy was evaluated by actuarial methods using first seizure relapse after onset of treatment to indicate unfavorable prognosis. In addition, a maximum interval of complete seizure control was calculated and related to length of follow-up in order to grade the severity of the disease (defined as mild, moderate, or severe). The average length of follow-up was 21.6 months (range 2-40). Seizure relapse occurred in 52% of cases during follow-up (36% by 3 months, 43% by 6 months, and 49% by 12 months). A larger number of seizures before therapy and the presence of combined seizure patterns were the variables most commonly associated with relapse. In general, epilepsy was mild in 65% of the cases, moderate in 28%, and severe in 7%. The earlier the first relapse the higher the risk of developing more severe disease. A larger number of seizures before treatment, combined seizure types, earlier age at onset, and prolonged disease duration (1 month to 1 year) seemed to be more frequently associated with the development of moderate-to-severe epilepsy.