Fifty former amateur boxers were examined and compared with two control groups of soccer players and track and field athletes. All subjects were interviewed regarding their sports career, medical history, and social variables. They underwent a physical and a neurologic examination. Personality traits were investigated and related to the platelet monoamine oxidase activity. Cerebral morphologic changes were evaluated using computed tomography and magnetic resonance imaging. Further, clinical neurophysiologic tests were made as well as neuropsychologic tests. No significant differences were found between the groups in any of the physical or neurologic examinations or in platelet monoamine oxidase activity. Socially, the boxers had a lower degree of education and had chosen less intellectual professions, but they were less impulsive and more socialized. The computed tomography images and magnetic resonance imaging studies showed no significant differences between the groups. There was a significantly higher incidence of slight or moderate electroencephalography deviations among the boxers. Neuropsychologically, the boxers had an inferior finger-tapping performance. Thus, no signs of serious chronic brain damage were found among any of the groups studied. However, the electroencephalography and finger-tapping differences between the groups might indicate slight brain dysfunction in some of the amateur boxers.