Physicians in the United States should familiarize themselves with "kissing bugs" endemic to their area of practice and appreciate the medical implications of their bites. Bite victims often seek advice from physicians about allergic reactions as well as the risk of contracting Chagas disease. Physicians are generally knowledgeable about the role of kissing bugs in the transmission of Trypanosoma cruzi in Latin America. However, they may be unaware of (1) severe allergic reactions to kissing bug salivary antigens, (2) the widespread occurrence of T. cruzi amongst vertebrate hosts of kissing bugs, and (3) the incidence of T. cruzi among kissing bugs (T. cruzi may infect >50% of sampled bugs). Despite the potential for Chagas disease transmission, the major concern regarding kissing bugs in the United States is anaphylactic reactions to their bites resulting in frequent emergency department visits, especially in areas of endemicity in the Southwest.