We sought to examine correlations between international backpackers' alcohol consumption and sexual behaviors and determine the prevalence of Chlamydia trachomatis and Neisseria gonorrhoea in this population. A cross-sectional study design consisting of a convenience sample (N = 168) of non-treatment-seeking international backpackers visiting Brisbane, Australia was recruited. Participants were asked to self-complete a questionnaire on sexual behavior and to undertake a urine-based polymerase chain reaction test for C trachomatis and N gonorrhoea. Since arriving in Australia, 73.2% reported having had sex, with a median number of 2 different sex partners (range = 0-21). Most participants had consumed alcohol (53.7%) and used condoms (46.3%) the last time they had sex. In our sample, there was a 4.3% prevalence of C trachomatis and a 0% prevalence of N gonorrhoea. This study identified a variable pattern of risk among backpackers, with those spending longer periods in the country more likely to have sex with Australians.