Acute lung injury (ALI) is a complex syndrome involving the interplay of both environmental (such as the addition of mechanical ventilation) and genetic factors. Clinical models have identified risk factors for development and poor outcome but these strategies remain imprecise. To better understand the mechanisms of pathogenesis associated with mechanisms of ALI, candidate genes identified by global expression profiling or related literature searches are being explored for relevant polymorphisms (single base pair substitutions) that can affect both ALI susceptibility and outcome. This article summarizes several specific genetic association studies that have been conducted in ALI and reviews supporting data from in vitro and in vivo models of the disease and clinical observations. Although valuable information has been reported to date, intense analyses are needed in this developing discipline to assure significant clinical utility. The detailing of specific associated polymorphisms will continue to provide new insights in the understanding of disease pathogenesis, and promise to reveal novel molecular targets and personalized treatments to prevent the disease.