Objectives: To evaluate the value of neutrophil left shift parameters and neutrophil morphologic changes in diagnosing acute bacterial infections. Materials and Methods: Peripheral blood samples were obtained from 105 patients who had a positive culture for bacteria. Automated complete white blood cell count was performed as well as peripheral blood smear preparation. Absolute neutrophil count (ANC) and neutrophil band count were determined and the neutrophils were evaluated for morphologic changes, namely toxic granulation, vacuolation and Döhle bodies. Results: Band count was less sensitive than ANC and white blood cell count in predicting bacterial infections except in the elderly and infant population. Toxic granulation in neutrophils appeared to be as sensitive as ANC in predicting bacterial infection. Conclusion: ANC and toxic granulation appear to be more sensitive than band count in predicting bacterial infections. However, band count has a greater sensitivity in infants and elderly patients.