Abstract Background The incidence of cancer is increasing worldwide, which has led to greater public health focus on primary prevention. Ethnic minorities have lower awareness of cancer risk factors and services, and are at greater risk of cancer mortality. While Gypsies, Roma and Travellers have poor health outcomes even in comparison with other ethnic minorities, little is known about how they view and enact primary prevention. This study takes a participatory approach to explore knowledge and experience of cancer prevention and screening in these communities. Methods Peer researchers conducted interviews (n = 37) and a focus group (n = 4) with a purposive sample of community members in Wales and South-West England. Participants self-identified as Roma (from Slovakia and Romania) or as Gypsies, Travellers or Showpeople (here described as Gypsy/Travellers). A third of the sample were Roma, and a quarter male, with ages ranging from 18 to 77 years. Data were collected from October 2018 to March 2019. Results Women and men knew that lifestyle factors, such as healthy diet, stopping smoking, drinking less alcohol and using sun protection, contribute to cancer risk reduction. However, there was a widespread lack of confidence in the effectiveness of these measures, particularly in relation to smoking. Traditional cultural beliefs were shared by Roma and Gypsy/Travellers, but did not necessarily affect the behaviour of individuals. Most women participated in cervical and breast screening but few Gypsy/Traveller men would engage with bowel screening, which conflicted with community ideals of stoical masculinity. Roma participants described language barriers to screening, with confusion about differences in timing and eligibility between the UK and Slovakian programmes; this led some to access screening abroad. Conclusion This study provides new knowledge about how Gypsies, Roma and Travellers keep healthy and prevent disease, giving insights into similarities and differences between ages, sexes and communities. These culturally distinct and high-need ethnic minorities have specific needs in relation to cancer prevention and screening, which merit targeted and acceptable health promotion to reduce health inequalities.