Child abuse and neglect include four distinct conditions: physical abuse, neglect, emotional abuse and sexual abuse. The magnitude of the problem is not well defined. The lack of epidemiological data limits the extent to which sound public health and social welfare policies and intervention programmes could be developed, implemented and evaluated. In recent years two approaches have been developed to document the magnitude and nature of child abuse and neglect: regional or national case registers; and a screening instrument for suspected cases of child abuse and neglect (SCAN) for use in health service facilities. We are proposing an additional approach for monitoring presumed child abuse and neglect-related mortality. Applying this approach to regions or groups of countries for which there are sufficient data, the expected under-5 rate of presumed child abuse and neglect would be between 13 and 20 per 100,000 live births. These estimates are higher than those made either from community-based registers or forensic reporting systems. Differences in these estimates will need to be resolved through further research. Injury and injury-related mortality can be classified as intentional, unintentional or resulting from varying degrees of neglect. Death from physical abuse represents a willful act or series of actions. Death from neglect may arise from willful behaviour but may also arise from ignorance and irresponsible behaviour. These include failure to recognize hazardous circumstances or children's nutritional, health and developmental needs, and leaving infants and children unattended or inadequately supervised. Mortality data provide virtually no measure of sexual abuse.(ABSTRACT TRUNCATED AT 250 WORDS)