Background: Sexual behavior of travelers to Latin America and the sexual behavior of US travelers in general are poorly characterized. Goal: The goal of the study was to evaluate sexual risk factors of travelers to Peru. Study Design: Anonymous written questionnaires were administered to 442/507 (87%) of the individuals approached in the international departures area of the Lima airport. Results: Of the 442 respondents, 54 (12.2%) had new sex partners during their stay. Sex with a local partner (35/52; 67.3%) was more frequent than sex with other travelers (18/52; 34.6%) or with sex workers (4/52; 7.7%). Risk factors for a new sex partner included male sex (relative risk, 1.94), single marital status (relative risk, 2.59), duration of stay longer than 30 days (relative risk, 5.05), traveling alone or with friends (relative risk, 2.88), and bisexual orientation (relative risk, 4.94). Frequency of sexual activity among US travelers was greater than that among travelers from other countries (15.2% [22/145] versus 10.6% [30/282]; NS). Condoms were consistently used by 12/50 (24%) and sometimes used by 10/50 (20%), including 8/20 United States travelers and 13/29 travelers from other countries. Conclusion: Behaviors and risk factors are similar to those described for travelers to Africa, Asia, and Eastern Europe. Behavior of US travelers did not differ from that of other travelers.