OBJECTIVES: To describe the prevalence of ADHD in mothers of children with comorbid ADHD and epilepsy (ADHD+E) and to compare ADHD symptoms in mothers with (Fam(+)) and without (Fam(-)) additional relative(s) with epilepsy. PATIENTS & METHODS: Mothers (n = 16) of children with ADHD+E were assessed by the Kiddie Schedule for Affective Disorders and Schizophrenia for School Age Children ADHD module and the ADHD Rating Scale IV. Information was collected on the presence (Fam(+)) or absence (Fam(-)) of first- or second-degree relatives with epilepsy in the sample. RESULTS: A total of 50% of mothers met the DSM-IV criteria for ADHD. ADHD was more prevalent in Fam(+) mothers (80%) compared with Fam(-) mothers (36%; p = 0.14). Fam(+) mothers had more current hyperactivity symptoms than Fam(-) mothers (p = 0.002), higher current ADHD severity (p = 0.02) and higher ADHD Rating Scale IV hyperactivity scores (p = 0.008). CONCLUSION: The prevalence of ADHD in mothers of children with ADHD+E is elevated in this pilot study, suggesting that ADHD symptoms in children with epilepsy and their mothers reflects shared familial genetic or environmental risks, potentially resulting in a higher prevalence of both disorders among family members. This is a pilot study and larger controlled studies are warranted.