This study investigates sexual behaviour and the risk of contracting sexually transmitted diseases among travellers departing from Hong Kong, with an aim supporting the design of local intervention in continuing health promotion. Travellers were interviewed by five trained multilingual interviewers in the departure lounge at Kai Tak International Airport, Hong Kong, between May and June 1996, by using a structured, pretested questionnaire. Forty-four percent (168/383) of the respondents who travelled at least once within the previous year had had sex with strangers during their travel and 37% (139/376) of the respondents reportedly do not use condoms during sexual intercourse. Middle-aged and married travellers were more likely to be in the high-risk group. These findings reflect the urgent need to target travellers in any strategy that is designed to prevent the spread of sexually transmitted diseases in Hong Kong and Asia Pacific region.