Background: Heart failure (HF) is a global health problem associated with marked increase in mortality, morbidity and healthcare costs with frequent hospitalization. Patients at high risk for complications on hospital admission should be identified early for optimal care and better outcomes. The aim of this work was to assess the value of admission complete blood count (CBC) in predicting the occurrence of complications in patients admitted to hospital with acute heart failure (AHF). Methods: This study was conducted on 210 patients hospitalized with AHF over a period of one year, Patients were classified into two groups according to the presence of complications at admission or during their hospitalization into: group 1 (Non-complicated group) including 191 patient and group 2 (complicated group) including 19 patients, the results of admission CBC were correlated with outcomes. Results: A statistically significant correlation was found between poor outcomes in hospitalized AHF patients and the following hematological parameters; Decrease in Hemoglobin concentration (Hb), increase in Neutrophils percentage, decrease in Lymphocytes percentage, increase in the Neutrophils to lymphocytes ratio (NLR), and increase in the Red cell distribution width (RDW). Conclusion: A simple CBC on admission can be used as a single test for the prediction of short term outcomes in patients hospitalized with AHF.