Acute respiratory distress syndrome (ARDS) is one of the devastating sequelae of sepsis, and so far no specific promising pharmacotherapies have been proven to decrease mortality from it. Stem cell therapy is a novel therapy that can promote earlier and more effective remodeling and repair of damaged lung tissue. Bone marrow-derived mononuclear cells are an alternative stem cell therapy that is safely and easily administered on the day of harvesting and yields benefits in acute disease processes like ARDS. In a recent issue of Stem Cell Research and Therapy, Maron-Gutierrez and colleagues demonstrated that the effects of transfused bone marrow-derived mononuclear cells on lung mechanics, inflammation and mortality might be different in different septic ARDS models due to different insults.