Background <p>High-quality preventive nursing care and improved patient safety outcomes are more likely to be achieved by nurses who are knowledgeable about the risks associated with immobility and the evidence-based strategies for preventing and managing immobility-related complications. However, previous studies have reported variations in nurses’ knowledge and attitudes regarding patient immobility and its complications across different healthcare settings, highlighting areas for potential improvement. This study aimed to assess nurses’ Knowledge, Attitude, and Practice (KAP) toward immobility complications at King Fahad Hospital in Jeddah (KFHJ), Saudi Arabia.</p> Methods <p>A quantitative descriptive cross-sectional study was conducted using a convenience sample of 212 nurses at KFHJ. Data were collected using a previously developed and validated questionnaire, consisting of four parts: sociodemographic and work-related characteristics, knowledge, attitudes, and practices regarding immobility complications.</p> Results <p>Participants demonstrated adequate knowledge (82.1%, mean = 13.7 ± 2.7), negative attitudes (57.5%, mean = 12.4 ± 2.9), and good practices (61.8%, mean = 24.4 ± 4.3) toward immobility complications. Nurses who had received previous training were significantly more knowledgeable about major immobility complications than those who did not, with an odds ratio of 3.1. A significant positive correlation was found between the knowledge and practice scores, while no significant correlation was found between the practice and attitude scores and between the knowledge and attitude scores.</p> Conclusion <p>Training was associated with improved Knowledge, Attitude, and Practice levels. This finding highlights the need for in-service training and educational intervention to strengthen preventive nursing care and reduce immobility-related complications.</p>