Abstract Introduction: Liaison Nurse is a new nursing role equipped with the knowledge, skills and competenciesto provide care for patients in the intensive care unit(ICU) and ensure continuity of care in other hospital units.This study aimed to clarify the concept of the liaison nurse's role in the ICU. methods: This study used Rogers' evolutionary approach. A search was conducted in the English databases Web of Science, ScienceDirect, ProQuest, PubMed, Scopus, and Embase, and the Persian databases IranMedex, SID, and Magiran from 2013 to 2024 using keywords such as "nurse liaison," "critical care," and "concept analysis" along with their English equivalents. Finding: The concept of the Liaison Nurse is synonymous with "unlimited intensive care," "removing boundaries," and "filling the care gap." Antecedents include experienced nurses holding at least a bachelor's degree and expertise across various clinical and care fields. The consequences involve bridging the gap between the ICU and other units through enhanced communication, continuity of care, reduced length of hospitalization, improved transfer quality, decreased patient anxiety, and increased patient satisfaction. Conclusion: The Liaison Nurse role is a novel concept in Iran, positively impacting patient outcomes. However, it faces challenges such as limited human resources and budget constraints. It is therefore recommended that this role be widely implemented across various hospital departments through comprehensive programs to maximize its benefits.