CONTEXT: In the United States, 10% of the population was born outside of its borders. Immigrants and their children frequently return to visit their homeland, referred to as visiting friends and relatives (VFRs). They account for a disproportionately high volume of international travel. EVIDENCE ACQUISITION: Searches of MEDLINE, World Health Organization, Centers for Disease Control and Prevention, International Society of Travel Medicine, and American Society of Tropical Medicine computerized databases, conference proceedings and abstracts, US Census Bureau, bibliographies of pertinent articles, and travel medicine texts. Priority was given to recent (1996-2003) evidence, addressing VFR travelers. General sources including travel medicine and immigrant health were also used. EVIDENCE SYNTHESIS: Immigrants visiting friends and relatives experience excessive rates of travel-related morbidity and mortality. Lack of pretravel care is common due to patient and clinician barriers to care, preexisting health beliefs, and incomplete childhood vaccinations. Travel patterns increase risk with VFRs traveling to high-risk destinations. Susceptibility to infectious and noninfectious illnesses is often increased because of multiple preexisting medical problems and extremes of age. Infectious diseases differ in etiology and magnitude from those of traditional travelers. For example with malaria, VFRs are frequently prescribed inappropriate prophylaxis or take none at all, have longer stays, spend time in high-risk areas, and do not appropriately adhere to chemoprophylaxis regimens. Effective pretravel health advice, guidelines, and services for this high-risk population are essential. There are already a number of useful and readily available databases that may aid clinicians in providing optimal travel-related preventive and therapeutic care. CONCLUSIONS: Immigrants who are visitors of friends and relatives in other countries account for a high volume of international travelers and are at markedly increased risk of travel-related illness. New strategies are needed to properly address the needs of VFR travelers. Pretravel services should be convenient, accessible, affordable, culturally competent, and if possible, located within clinics serving immigrant populations. Clinicians caring for VFRs should be knowledgeable about their travel-related risks and have access to regularly updated, detailed pretravel health information.