Actions to prevent injury may address either individual behaviour or population practice. Factors associated with injuries in a variety of circumstances may be best suited to prevention at the level of population whereas more specific causes would not be. Data from the Ontario Health Survey were used to assess the similarities and differences between risk factors and injury in traffic crashes, at work and in other circumstances. Respondents reporting injury were compared with age- and sex-matched controls reporting no injury for reported alcohol ingestion, binge drinking and drinking and driving. In addition, data on the use of licit and illicit drugs, occupation and other demographic factors were compared. Variables showing consistent associations with injury included drug use, some measures of alcohol ingestion and reports of co-existing chronic disease. Many variables showed a variable pattern, including occupation, education and income. In many instances, these differences reflected differences in exposure to risk. Efforts at prevention related to alcohol or medication could be broadly based, whereas for other factors, more targeted prevention efforts would be appropriate.