<h4>Objective</h4>This study aimed to investigate the association between the C-reactive protein to albumin ratio (CAR) and unplanned readmissions in patients with ulcerative colitis (UC) and to evaluate its potential value as a predictive indicator.<h4>Methods</h4>This study included 412 patients with UC who were hospitalized at the Affiliated Hospital of Shandong University of Traditional Chinese Medicine between June 2017 and June 2024. Here, CRP is linked to ulcerative colitis.