The authors report on a father and son with frontal lobe epilepsy and symptoms of attention deficit hyperactivity disorder (ADHD). Attention deficit hyperactivity is a syndrome defined by criteria that include inattention, impulsive behavior, impaired concentration and motor restlessness. It does not require medical or neurobehavioral evaluation to determine an underlying etiology. The father is a 45-year-old man evaluated for possible ADHD. His referral came after the diagnosis of ADHD in his 6-year-old son who responded well to treatment with methylphenidate HCL. Neurobehavioral evaluation of the father suggested frontal lobe dysfunction. Magnetic resonance imaging and electroencephalography (EEG) were normal. Brain 99mTc HMPAO single-photon emission computed tomography (SPECT) revealed left orbitofrontal hypoperfusion. Additional history from his wife revealed episodic symptoms suggestive of nonconvulsive epilepsy that included nonresponsive staring, complex automatic behavior, and amnesic lacunas. Treatment of the father with carbmazepine produced dramatic improvement. Subsequent evaluation of his son, currently on maintenance treatment with methylphenidate HCL for ADHD, elicited a history consistent with atonic and simple motor partial epilepsy. The son's brain SPECT revealed bilateral orbitofrontal hypoperfusion defects. Attention deficit hyperactivity disorder is a syndrome that may be caused by frontal lobe lesions or epilepsy. In the setting of possible ADHD, neurological evaluation is warranted. Although overreliance on structural imaging or EEG in such an evaluation must be discouraged, brain SPECT may be useful to evaluate patients with symptoms of attention disorders for frontal epilepsy.