Background: A growing number of older people, mainly women, live in single households. They represent a vulnerable group as staying at home may turn out challenging when care needs increase, particularly at the end of life. Non-kin-carers can play an essential role in supporting individuals’ preferences to stay at home. In research little attention has been paid to non-kin-carers, such as friends and neighbors, yet. Thus, the Older People Living Alone (OPLA) study will evaluate whether non-kin support is robust enough to enable care dependent people to stay at home even at the end of life. This paper aims to introduce the research protocol. *** Methods: We plan to apply a qualitative longitudinal study to better understand how older people living alone and their non-kin-carers manage to face the challenges with increased care needs towards the end-of-life. We will conduct serial interviews with the older persons living alone and their non-kin-carers. A total of 20–25 complete data sets and up to 200 personal interviews were planned. These will be complemented by regular telephone contacts. All interviews will be analysed following the grounded theory approach and strategies for reconstructing case trajectories, supported by MAXQDA software. In the course of the study, inter- and transdisciplinary workshops shall assure quality and support knowledge transfer. *** Discussion: This study protocol aims to guide research in a field that is difficult to approach, with regard to its topic, methodology and the interdisciplinary approach. As this study introduces longitudinal qualitative research methodology in the field of home care in Austria, a deeper understanding of (end-of-life-) care trajectories will be enhanced, which is of major relevance for future care planning. With investment in additional reflexivity and communication procedures innovative results and robust knowledge are expected outcomes.