Objective: Post-intensive care syndrome is a term used to describe new or worsening multidimensional impairments in physical, psychological cognitive and social status arising from critical illness and persisting beyond hospital discharge. It is associated with high morbidity among patients discharged from intensive care units. However, due to its complexities, which encompass physical, psychological, cognitive and social impairments, the exact nature of this condition has not been fully conceptualized. The aim of this analysis therefore was to define the concept of post-intensive care syndrome. This conceptual clarity provides a general definition that is essential for practitioners and researchers to gain a comprehensive understanding of the syndrome and provide for accurate measurement of its incidence and prevalence. Design: The Walker and Avant approach to concept analysis guided this investigation. Data source: An electronic search of the literature using PubMed, CINHAL, PsycArticles, Academic search complete, Science Direct, MEDLINE and Health Source databases informed the analysis. The search included both quantitative and qualitative studies related to post-intensive care syndrome published in English between 2010 and 2020. Results: Of the 3948 articles identified, 24 ultimately met the inclusion criteria. Analysis identified the defining attributes of post-intensive care syndrome as: (1) new or worsening multidimensional impair- ments; (2) physical dysfunction; (3) psychological disorder; (4) cognitive impairment; (5) failed social reconstruction; and (6) persistent impaired multidimensional symptoms extending beyond intensive care and hospital discharge. Antecedents were divided into two categories: pre-existing and those related to the intensive care admission. Consequences were identified as both positive (for example the establishment of coping processes) and adverse (for example decreased quality of life and caregiver burden). Conclusion: Post-intensive care syndrome affects more than half of patients discharged from intensive care units. This operational definition and conceptual understanding of this syndrome will help improve understanding and inform the design of preventative strategies to improve long-term consequences of the syndrome. Future research and standardized instrument development will serve to better understand the scope and characteristics of this syndrome and inform the development of possible preventative interventions.