Sulfur mustard (SM), an alkylating chemical agent, targets several organs, particularly the respiratory system, and results in early and late toxic effects. Currently, there is a considerable lack of adequate medical countermeasures for SM-associated lung injury. Mesenchymal stem cells (MSCs) are characterized by their self-renewal properties and differentiation capacity into multiple cell lineages. These features provide MSCs with the unique ability to engraft into injured tissues and exert immunomodulatory and tissue-repairing effects. Recent congruent findings on the usefulness of MSCs in the context of SM-induced pulmonary injury have raised the promise of their therapeutic use; however, their potential protective mechanisms are still unknown. A better understanding of the therapeutic mechanism of MSCs involved in SM-pulmonary injury would help figure out new target options. Accordingly, this study discusses the opportunities and therapeutic mechanisms of MSCs in SM poisoning. Recent advances in the treatment of SM-induced lung injury and the therapeutic mechanisms of MSCs as possible new treatments are highlighted. The PubMed and Scopus databases for published studies on the therapeutic approach of SM-induced lung manifestations were searched with a focus on the therapeutic mechanisms of MSCs.