In acute heart failure (AHF), hemoglobin, red cell distribution width, mean platelet volume, leukocytes, and relative lymphocyte count have been associated with mortality. It is not known whether absolute blood neutrophil, eosinophil, and monocyte counts are mortality predictors. One hundred and seventy-six patients hospitalized due to AHF were enrolled. Treatment modalities and comorbidities influencing leukocyte counts were excluded. Hemogram, pro-brain natriuretic peptide, D-dimer, biochemistry, thyroid hormones, sensitive C-reactive protein, and echocardiography were obtained. Cardiovascular deaths during the first year after hospitalization were determined. Leukocyte and absolute neutrophil count were significantly higher and absolute lymphocyte count and absolute eosinophil count (AEC) were significantly lower in deceased patients than patients who survived. Groups were similar in terms of monocyte counts. BMI albumin, estimated glomerular filtration rate, free T3, ejection fraction were significantly lower, and ferritin, uric acid, D-dimer, pro-brain natriuretic peptide were significantly higher in deceased patients. Mitral regurgitation, hypotension, hyponatremia, and acute renal failure were also significantly more frequent among the deceased group. Binary logistic regression analysis employing significant variables showed that lower BMI, lower ejection fraction, hyponatremia, lower free T3, and lower AEC were independent predictors of death and as a whole were responsible from 81.8% of cardiovascular deaths. Death rate among patients with an AEC of 0.02 n/l×10 or less was 4.4-fold higher than patients with an AEC of more than 0.02 n/l×10. AEC of AHF patients measured at admission was found to be a stronger predictor of mortality than all other hemogram parameters and this is consistent with the increased sympatho-adrenal activity theory.