Posttravel screening is the clinical and laboratory assessment of an individual aimed at uncovering occult infections, pathology, or health risks, the treatment of which will yield a significant health benefit to the individual. Screening must be tailored to the different risk patterns associated with different travel categories (e.g., missionary, tourist). Screening, predominantly a secondary prevention strategy, is most cost-effective when integrated with primary prevention strategies aimed at preventing future travel related illness (Table 6). The screening process begins with a medical history that allows a definition of risks and a tailored approach to laboratory tests. The screening tests currently available for STDs, tuberculosis, and parasitic infections have been reviewed, and although cost-effectiveness data are not available for most post-travel screening tests, recommended approaches are proposed. Traditionally, screening has been directed at uncovering occult infectious disease (STDs, tuberculosis, and parasitic infections). Important benefits can be gained, however, by including screening questions and tests for those diseases that are the major causes of mortality, both in nontraveling and in traveling North Americans, that is, the atherosclerotic and neoplastic diseases and trauma, especially vehicular.