OBJECTIVE To investigate frequency of sexual encounters with new partners abroad in patients attending a genitourinary clinic (GUM). METHODS In a case series 464 attenders at a genitourinary medicine clinic completed an anonymous self-administered questionnaire, if they had been abroad recently, enquiring about sexual behaviour abroad. RESULTS 28.4% of subjects admitted to sex with a new partner abroad with only 41.7 per cent consistently using condoms. There were no significant differences in condom use for gender, ethnicity or type of visit and relationship. Twenty-nine per cent of those admitting to sex abroad had more than one partner. The risk of multiple partners was not associated with gender, ethnicity, type of visit (holiday or business) or type of relationship (heterosexual or homosexual). The first partner abroad for 63% of men and 62.5% of women was of a nationality other than that of United Kingdom residents. Non-Caucasians and homosexuals were significantly more likely to have first partners abroad from outside the UK than Caucasians and heterosexuals respectively. CONCLUSIONS The occurrence of casual sex abroad in GUM attenders suggests that further research is needed to establish targetable risk factors for this type of behaviour amendable to change through health promotion.