Sepsis is one of the most unreachable conditions of hospitalization and a major contributor to hospital mortality, representing a major worldwide health burden. Sepsis is a syndrome characterized by an irregular host response to pathogens invasion, which involving hemodynamic changes that lead to multiple life-threatening organ dysfunctions. Among the injured organs, the lung is the first and most frequent organ to fail. Acute respiratory distress syndrome (ARDS) develops with many serious medical disorders. At least, mortality is 40% and there is no specific therapy. ARDS is an acute inflammatory process in the lung caused by infection direct or indirectly to the alveolar-capillary membrane. Currently, ARDS is diagnosed based on a combination of clinical and physiological variables. In this article, we will review the current understanding of surfactant protein-D as one of many biomarkers in ARDS diagnosis.