INTRODUCTION: Use of antibiotics is high in Samoa and this may affect the expectations and patterns of antibiotic use of Samoans in New Zealand. AIM: This study examined the understanding and reported use of antibiotics amongst Samoans in New Zealand. METHODS: In-depth interviews were held with 13 Samoans in New Zealand. These interviews were analysed and used to develop a questionnaire that was administered to 112 Samoans attending health care facilities in New Zealand. RESULTS: Many participants had little understanding of antibiotics. Less than 2% identified the correct purpose for antibiotics, and 66% thought they were used to relieve pain. Respondents regarded a wide range of medicines (including some which they regularly took) as antibiotics. They frequently attributed colds and flu to environmental conditions (96%), and regarded antibiotics as a useful treatment for them (81%). They reported stopping taking antibiotics before finishing the course. Very few (8%) were aware of antibiotic resistance. DISCUSSION: Health care practitioners cannot assume that patients share a Western scientific understanding of which illnesses are caused by microbes, or what antibiotics are or do. People may have significant confusion about the medicines they take. Samoans, whether they are born in New Zealand or not, may hold traditional Samoan views about health and illness. KEYWORDS: Antibiotics, lay knowledge, URTI (upper respiratory tract infections), Samoa, New Zealand