Background <p>Missed nursing care (MNC) can significantly impact patient outcomes and care quality. While most studies focus on the nurses’ perspective, limited research explores how patients perceive missed care. Understanding MNC from both patients’ and nurses’ viewpoints can provide a more comprehensive perspective of care quality and help improve nursing practices. The aim of this study was to compare patients’ and nurses’ perceptions of missed nursing care, to identify the most frequently missed care needs and their reasons, and to examine the association between missed nursing care and adverse events.</p> Methods <p>The study was a descriptive cross-sectional study. The sample consisted of patients (n=323) and nurses caring for them (n=30). Patient Information Form, Nurse Information Form, Missed Care (MISSCARE-Adverse event) Survey-Patient, and Missed Care (MISSCARE) Survey-Nurse were used to collect data. The Statistical Analysis System version 9.4 program was used for statistical analysis of the data.</p> Results <p>The mean score of patients' missed nursing care was 2.11±0.49, and the basic care subscale was the highest missed care. The mean score for the nurses from the first part of, "missed nursing care" scale was 1.65±0.55, and the mean score for the second part, “reasons for missed care, was 3.25±0.48. The “human resources” ranked first with the highest score among the reasons for missed care reported by nurses. A total of 68.4% of patients experienced adverse events, and those who experienced adverse events reported more missed nursing care than those who did not. (p˂0.01).</p> Conclusion <p>The basic care reported by the patients as the most common missed care is the care that is not met by the nurses. It was found that nurses reported missed care at a lower rate than patients and that insufficient human resources were the most important reason for missed nursing care. Patients who experienced adverse events reported that their care was not met more often than those who did not.</p>