Clinical nursing supervision enables supervisees to reflect on ethically difficult caring situations, thereby strengthening their professional identity, integrating nursing theory and practice, and leading to the development of ethical competence. The aim of this study was to develop an understanding of the core ethical issues of clinical nursing supervision, using previous research as well as philosophical analysis of the theories of three moral philosophers: Harald Ofstad, Richard Hare and Carol Gilligan. The ultimate aim of this study was to develop a general model for ethical decision-making and to establish its relevance for clinical nursing supervision. The findings highlight four important values for the development of a basis for ethical decision-making. These values are caring, dignity, responsibility and virtue.