Objective To explore predictive value of baseline red cell distribution width (RDW) determined in a routine blood count for severity of chronic heart failure (CHF) and mortality during hospitalization. Methods The study group comprised 135 patients hospitalized in the our hospital with CHF in the Ⅱ~Ⅳ class according to New York Heart Association (NYHA). The control group included 44 patients in class Ⅰ. Hematological and biochemical parameters were obtained and compared among groups. Receiver operator characteristic (ROC) curves were used for assessing predictive values. Results RDW increased significantly in class Ⅲ and Ⅳ compared to class Ⅰ [(14.3±2.3)% and (14.3±1.7)% vs (12.9±0.8)%, P<0.01=. Areas under ROCs (AUCs) of RDW, N-terminal prohormone brain natriuretic peptide (NT-proBNP) for class Ⅳ HF was 0.817 and 0.840, respectively. RDW was significantly elevated in mortality group compared to survival group [(15.8 ± 1.8)% vs (13.7 ± 1.7)%, P<0.01=, predictive value of RDW was lower than that of NT-proBNP but was comparable to white blood cell (WBC), neutrophil (NEU), lymphocyte (L), and neutrophil /lymphocyte ratio (N/L) for mortality during hospitalization with AUCs (0.837, 0.939, 0.858, 0.891, 0.885, and 0.885, respectively). RDW and NT-proBNP showed low predictive values for repeated admission (≥3). RDW was an independent risk factor for mortality (OR=2.531, 95% CI: 1.371~4.671). Conclusions RDW increased significantly in class Ⅲ and Ⅳ patients and death group. The predictive value of RDW is comparable to NT-proBNP for class Ⅳ and lower than that of NT-proBNP for mortality. Elevated RDW is an independent risk factor for mortality. Key words: Erythrocytes; Heart failure