Background <p>Missed nursing care (MNC) in the operating room (OR) threatens patient safety because of workflow complexity, time pressure, and limited communication with patients. Although quantitative studies have described the prevalence and correlates of MNC, less is known about how OR nurses experience and interpret these omissions in daily practice. This study explored OR nurses’ experiences of MNC and the contextual, organizational, and individual factors shaping their responses.</p> Methods <p>This qualitative phenomenological study included 15 operating room nurses from a tertiary teaching hospital in Anhui Province, China. Data were collected through semi-structured interviews and analyzed using Colaizzi’s seven-step method. Reporting followed the COREQ checklist.</p> Results <p>Three overarching themes were identified. Missed nursing care was shaped by interacting system-, team-, and individual-level factors, including staffing shortages, workflow interruptions, communication gaps, cognitive overload, and emotional fatigue. Nurses described a paradoxical coping pattern of defensive concealment alongside silent critical reflection.</p> Conclusion <p>The findings suggest that missed nursing care in the operating room is shaped more by interacting system-, team-, and individual-level vulnerabilities than by individual negligence alone. Strengthening staffing, workflow design, communication, and a non-punitive safety culture may help reduce care omissions and improve perioperative safety.</p> Clinical trial number <p>Not applicable.</p>