Background: When there is a lack of resources in the community to support deinstitutionalisation, the siblings of an individual with a mental illness are the ones who are the most affected and vulnerable. Nevertheless, sibling care work is still largely unacknowledged in the mental health sector in low- and middle-income countries.Aim: This article describes and interprets the lived experiences of ‘black’ isiXhosa-speaking individuals having a sibling with a mental illness, to shed light on how mental health professionals might support and sustain the involvement of individuals in the treatment and care of their sibling.Setting: The study was conducted in a semi-rural town in the Eastern Cape of South Africa.Methods: The study employed a qualitative research design using interpretative phenomenological analysis as the research method. Semi-structured interviews were conducted and analysed.Results: The findings present interview extracts which give voice to participants’ experiences of financial burden, social burden and stigma, and of engaging with psychiatric treatment while providing care for their mentally ill sibling. Findings also highlight the positive aspects of caring for a sibling with a mental illness.Conclusion: This study specifically highlights the gendered nature of care work and siblings’ increased understanding of mental illness by virtue of their relationship with their brother or sister, thereby possibly pointing to sibling relationships as valuable relational resources for challenging stigma. The study findings suggest that calls for greater cooperation between healing belief systems should include dialogue with western religious belief systems alongside traditional healing belief systems.