Background The number of non-Western immigrants with breast cancer in the Netherlands has increased over the past decades and is expected to triple by 2030. Due to insufficient representation in clinical studies, it is unclear what the specific experiences and needs of these women are. Understanding how culture and religion affect these women's experience of breast cancer and how they deal with chemotherapy and treatment-related changes in body weight and lifestyle is crucial for health care professionals to be able to provide effective support. Methods A qualitative study was conducted using semi-structured interviews with 28 immigrant women with a history of breast cancer treated with chemotherapy. Results Women often associated breast cancer with taboo, death or bad luck. Religion offered these women guidance, strength and meaning to the disease, but also limited the women to openly talk about their disease. Women perceived lifestyle factors to have little influence on the development and treatment of cancer. After treatment, however, their thinking changed and these lifestyle factors became of paramount importance to them. They realised that they missed out on information about managing their own diet, exercise and body weight and were eager to share their experiences with other women in their culture with newly diagnosed breast cancer. Conclusion Women became aware during and after breast cancer treatment that it was difficult for them to actively deal with their illness under the influence of their culture and religion. Based on their own experiences and acquired knowledge, they would like to give advice to newly diagnosed women on how to deal with breast cancer within their own culture and religion. Their recommendations could be used by mosques, churches, support groups and health care professionals, to ensure interventions during breast cancer treatment meet their religious and cultural needs and thus improve their quality of life.