Sulfur mustard (SM) is a notorious chemical warfare agent that can cause severe acute lung injury (ALI), in addition to other lesions. Currently, effective medical countermeasures for SM are lacking. Bone marrow-derived mesenchymal stromal cells (BMSCs) possess self-renewal and multipotent differentiation capacity. BMSCs can also migrate to inflammation and injury sites and exert anti-inflammatory and tissue repair functions. Here, we report the curative effect of BMSCs on SM-induced ALI in a mouse model.