Sexually transmitted diseases (STDs) continue to be the most common notifiable infectious conditions worldwide. Their unacceptably high incidence is underlined by the recent emergence of a (presently) incurable and lethal STD--human immunodeficiency virus (HIV) infection--which merits its description as a pandemic, and with which other STDs interact in an epidemiological synergy. Data that quantify the association between STDs/HIV infection with travel and difficult to obtain; nevertheless figures are presented that reveal the lower limit to be large enough to be of considerable concern. Studies from around the world show, overall, although knowledge of STDs is increasing amongst travellers, the level of knowledge has little to do with actual behaviour, with a modest increase in the use of condoms, but abundant evidence that a wide variety of sexual behaviours take place among travellers and with local inhabitants. Certain travellers, by virtue of their behavioural interactions with 'core-groups' of efficient transmitters, may have a high risk of acquisition of an STD/HIV. Worldwide, sexual health promotion for travellers is in its infancy; indeed, it could more accurately be merely described as 'sexual education'. A fresh approach is recommended, which includes comprehensive programme planning and outcome, impact, and process evaluations.