Thirty-seven former football players of the Norwegian national team underwent a neurological and electroencephalographic (EEG) examination to investigate the incidence of head injuries due to heading the ball. Sixteen players complained of protracted and permanent symptoms commonly attributed to the post-concussional syndrome: headache, irritability, dizziness, lack of concentration and impaired memory. A significantly increased incidence of EEG abnormalities was found in players compared with matched controls. The high incidence of EEG changes is probably the result of a cumulative effect due to repeated head traumas.