Safe use of medicines is relevant to all, but especially older people, primarily because they have ageing bodies that require more medicines and are therefore more likely to experience complications, including adverse drug interactions. Australia has a rapidly growing migrant older population composed of people with different beliefs about, and practices using, medicines. This paper presents qualitative findings from interviews and focus groups conducted with older Vietnamese-Australian women living in Sydney, Australia. The findings show how the women's health literacy influenced their medication use and explain the cultural reasons behind their decision to vary medicine use from that prescribed by their western trained doctors. Concern that health professionals do not favour combining western with traditional medicines led some participants to manage their medicines without advice from their doctor. The findings support recommendations to reduce the likelihood of adverse medication outcomes by increasing health professionals' cultural competence, encouraging patients to work with their doctor and report all medications taken, and increasing funding for research into the effects of combining western with traditional medicines.