Publicity about human immunodeficiency virus (HIV) infection in athletes has focused attention on the potential for transmission of blood-borne pathogens during sports and athletic competitions. Existing information suggests that the potential risk for such transmission is extremely low and that the principal risks athletes have for acquiring HIV and hepatitis B virus are related to off-the-field activities. Therefore, efforts to prevent transmission of blood-borne pathogens among athletes should emphasize prevention in off-the-field settings. We summarize technical and other information about this issue, and provide recommendations for the education of sports participants, for infection control in athletic settings, and for training of coaches and officials.