Background <p>Nurses face multi-level ethical challenges in complex clinical environments. However, current research lacks a holistic analysis of the interacting factors. To address this gap, this study applies the Social-Ecological Theory to develop a comprehensive analytical model.</p> Methods <p>This study employed a qualitative phenomenological descriptive design. Semi-structured interviews were conducted with 23 front-line nurses from six tertiary Grade A hospitals between December 2024 and February 2025. Data were analyzed using Colaizzi’s seven-step phenomenological method.</p> Results <p>A total of 23 nurses participated in the study. Three main themes that emerged from the analysis, encompassing a total of eight subthemes: (1) Macro-system challenges (policy, organizational, and cultural dimensions); (2) Meso-system challenges (nurse-physician, nurse-nurse, and nurse-patient relationships); and (3) Micro-system challenges (individual physiological and psychological factors, and professional competence). These subthemes were further detailed into 20 specific subcategories. Based on these findings, a three-tiered model was developed to conceptualize the multi-level nature of ethical challenges in nursing practice.</p> Conclusions <p>This study reveals the systemic nature of ethical challenges in nursing practice, which arise from the dynamic interplay of macro-institutional, meso-relational, and micro-individual factors. The developed multi-tiered model elucidates how structural deficiencies permeate professional relationships and become internalized as personal distress. These findings underscore the imperative for integrated, multi-level interventions that simultaneously address systemic policies, workplace culture, and individual competencies to mitigate moral distress and uphold ethical practice. Future research should test this model in diverse settings and evaluate the effectiveness of the proposed interventions.</p>