Family aggregation can help determine the risk of epilepsy among relatives. Our aims are to describe the prevalence of family precedents of epilepsy among the diagnosed patients' relatives of the first and second degree, and to look for an association with diverse clinical variables.Market descriptive prospective study in a transverse cohort of a Spanish population. The study included 71 patients who, besides fulfilling the clinical diagnostic criteria, had a video-electroencephalogram compatible with epilepsy and drug resistance. The following variables were gathered: the first or second degree of family history, the location (temporal lateral, temporal mesial, parietal, frontal) of the epileptic abnormality, age at diagnosis, and type of epilepsy. The frequency and percentage were calculated of every variable. The probability of recurrence in a relative of the first or second degree was calculated by means of the relative risk (RR).On the whole, the gender distribution was 34 (47.9%) males and 37 (52.1%) females, with ages of 28.3 ± 10.3 years and 34.3 ± 10.2 years, respectively. The prevalence of family aggregation of epilepsy was 28 (34.9%). Family aggregation was more probable among males (RR = 2.5), when the diagnosis of epilepsy was realized between 13 and 18 years old (RR = 1.7), or when the epileptogenic area is located in the temporal mesial zone (RR = 1.9).Our study supports the existence of increased risk of epilepsy among relatives of drug-resistant epileptic patients.