Four coin-operated breathalysers were place in licensed premises in the Northern Territory for six months to determine their impact on the behavioural intentions and attitudes of patrons, especially as they relate to drink driving. Interviews were conducted with 44 breathalyser users, 270 other patrons and staff at the licensed premises. The results showed support for the widespread availability of breathalysers in the Territory. The behavioural changes recorded as a result of patrons learning their alcohol readings were limited: one fifth of these with readings over 0.05 indicated they would drink less and one respondent reported a change in his intention to dive. Staff reported the breathalysers assisted the responsible service of alcohol by providing an objective measure of intoxication. It is noted that they utility of breathalysers in somewhat dependent of their promotion and maintenance.