Background <p>Missed nursing care, defined as the omission or delay of necessary nursing tasks, poses significant risks to patient safety and nurse well-being in the high-stakes environment of Intensive Care Units (ICUs). Despite its prevalence, the subjective experiences of ICU nurses encountering this phenomenon remain underexplored, particularly in high-acuity settings.</p> Aim <p>This study aimed to explore the lived experiences of ICU nurses regarding missed nursing care, focusing on their perceptions, emotions, and the contextual factors influencing care delivery.</p> Methods <p>A qualitative phenomenological approach was employed. Fifteen ICU nurses from three tertiary care hospitals in Urmia, Iran, were purposively sampled. Data were collected through semi-structured, in-depth interviews conducted between January 2024 and June 2025. Data analysis followed Colaizzi’s phenomenological method. Trustworthiness was ensured through member checking, triangulation, and adherence to COREQ guidelines.</p> Findings <p>The overarching theme, “The Haunting Echoes of Omitted Care,” encapsulates the pervasive impact of missed care on nurses’ professional and emotional lives. Four subthemes emerged: Relentless Systemic Pressures, Emotional Erosion Over Time, Moral Quagmires of Compromise, and Fragile Threads of Adaptation. These reflect the interplay of systemic, emotional, and ethical factors shaping missed care experiences.</p> Conclusion <p>Missed nursing care in ICUs is a complex phenomenon driven by systemic constraints and mitigated by nurses’ resilience. The findings highlight the need for targeted interventions, such as acuity-based staffing and ethics support, to reduce care omissions and support nurse well-being. Future research should explore longitudinal and cross-cultural perspectives to enhance care quality in critical settings.</p> Clinical trial number <p>Not applicable.</p>