Sepsis is a systemic syndrome induced by infection and leading to a widespread inflammation up to septic shock, multi organ failure, and death. Neutrophils are manly involved in the innate immune response and lymphocytes in the adaptive immune response. In sepsis, blood neutrophil count increases and the blood lymphocyte count decreases; thus, the neutrophil-to-lymphocyte ratio (NLR) has been suggested as an indicator of systemic inflammation. The NLR is advantageous in regard to simplicity, low cost, and availability compared to many other proposed biomarkers, which makes it promising for diagnosis of Severe sepsis. Platelet-to-lymphocyte ratio (PLR) is reported to be related to the outcome of intensive care unit (ICU) patients.