question: BACKGROUND In the ever-changing and complex healthcare environment, nurses encounter challenging situations that may involve a clash between their personal and professional values resulting in a profound impact on their practice. Nevertheless, there is a dearth of literature on how nurses develop their personal-professional values. AIM The aim of this study was to understand how nurses develop their foundational values as the base for their value system. RESEARCH DESIGN A constructivist grounded theory methodology was employed to collect multiple data sets, including face-to-face focus group and individual interviews, along with anecdote and reflective stories. PARTICIPANTS AND RESEARCH CONTEXT Fifty-four nurses working across various nursing settings in Indonesia were recruited to participate. ETHICAL CONSIDERATIONS Ethics approval was obtained from the Monash University Human Ethics Committee, project approval number 1553. FINDINGS Foundational values acquisition was achieved through family upbringing, professional nurse education and organisational/institutional values reinforcement. These values are framed through three reference points: religious lens, humanity perspective and professionalism. This framing results in a unique combination of personal-professional values that comprise nurses' values system. Values are transferred to other nurses either in a formal or informal way as part of one's professional responsibility and customary social interaction via telling and sharing in person or through social media. DISCUSSION Values and ethics are inherently interweaved during nursing practice. Ethical and moral values are part of professional training, but other values are often buried in a hidden curriculum, and attained and activated through interactions during nurses' training. CONCLUSION Developing a value system is a complex undertaking that involves basic social processes of attaining, enacting and socialising values. These processes encompass several intertwined entities such as the sources of values, the pool of foundational values, value perspectives and framings, initial value structures, and methods of value transference.