This dataset is derived from the MIMIC-IV database (Medical Information Mart for Intensive Care IV), version 3.0. This database is a publicly available, anonymised critical care clinical database that contains clinical information of patients admitted to the intensive care unit (ICU) at Beth Israel Deaconess Medical Center in Boston, Massachusetts, USA, from 2008 to 2022. All patient information has been de-identified in compliance with HIPAA privacy protection standards. The raw data can be accessed through the PhysioNet platform (https://physionet.org/content/mimiciv/3.0/). Objective: Atrial fibrillation (AF) is a common arrhythmia in critically ill patients, and its risk stratification is essential for prognosis. This study aimed to explore the association between estimated pulse wave velocity (ePWV) and all-cause mortality in critically ill AF patients. Design: A retrospective observational cohort study. Setting and participants: Data were extracted from the Medical Information Mart for Intensive Care (MIMIC)-IV 3.0 database (2008–2022). A total of 14,704 critically ill patients with AF were enrolled after applying inclusion and exclusion criteria. Primary outcome: All-cause mortality at 30 days and 1 year after ICU admission. Secondary outcome: All-cause mortality at 60 days and 90 days after ICU admission. Conclusion: ePWV is independently associated with all-cause mortality in critically ill AF patients and can serve as a simple, non-invasive indicator for risk stratification and prognostic evaluation in the ICU.