The population of Greenland has behavioural characteristics that indicate a high risk of HIV spread once HIV is introduced into the population. Much depends, however, on the degree of exposure from visitors, particularly in an initial phase. We used a national questionnaire survey of 4,680 randomly selected Danes between 18-59 years to study HIV risk behaviours among Danes with (+travellers) and without (-travellers) travel experience to Greenland. Median number of lifetime sexual partners was more than twice as high among male +travellers (median = 12 partners) compared to -travellers (median = 5; p < 0.0001) and also slightly higher among women (p = 0.03). Furthermore, a significantly higher percentage of male +travellers than -travellers reported prostitute contact (OR = 2.3 (95% CI: 1.4-3.9)), with a peak of 32.0% among men aged 40-49 years. A history of a sexually transmitted disease was three times (95% CI: 2.0-4.5) as common among +travellers as in -travellers. +Travellers were also significantly more likely to have visited other places outside Europe and Greenland, including HIV endemic areas (OR = 2.9 (2.0-4.1)). Overall, sexual contact with someone considered at high risk of HIV infection (a homo/bisexual man, intravenous drug user, prostitute, or previous or present resident of Sub-Saharan Africa) was reported by 33.5% of male +travellers compared to 15.6% of -travellers and among women by 9.7% and 5.0%, respectively. In conclusion, travellers tend to have more sexual partners and more sexual interaction with high HIV-risk group members than non-travellers.(ABSTRACT TRUNCATED AT 250 WORDS)