Boxing injuries can involve immediate adverse physical effects and also effects that do not emerge until days or weeks after the injury was inflicted. Fatal injuries associated with brief survival periods include subdural hemorrhages or intracerebral hematomas. The brains of boxers who die days or weeks later should not be dissected immediately after death, but should first be fixed in formalin, followed by the selection of multiple representative tissue blocked for embedding and staining with hematoxylin-eosin. The two kinds of impact that occur in boxing are classified as "central" and "oblique." Central impacts pass through the center of the head, which causes a linear acceleration of the brain within the skull. An oblique blow to the head causes both a side and rotational movement of the brain within the skull. The specific types of boxing head injuries discussed are facial injuries, eye injuries, and hearing impairment. The authors then discuss acute and chronic neurological clinical findings. The acute type of injuries result from either a knockout that results from a blow or series of blows that incapacitates a boxer for at least a count of 10 seconds; and a technical knockout, which results when the referee determines that a boxer has been injured to the point that he is unable to defend himself. Chronic injuries to boxers occur over time due to the cumulative effects of boxing injuries, and they often persist even with treatment. The paper concludes with a discussion of types of traumatic intracranial lesions that result from boxing blows. 13 photographic exhibits and 35 references