Excessive systemic inflammation following burns could lead to acute kidney injury (AKI). Mesenchymal stromal cells (MSCs) suppress immune cell responses and have beneficial effects in various inflammatory-related immune disorders. However, autologous MSCs are not vital enough for the treatment because of the severely burned patients’ deleterious condition. Umbilical cord–derived mesenchymal stem cells (UC-MSCs) could be a suitable substitute cell candidate but no data are available on the therapeutic effectiveness of UC-MSCs transplantation for burn injury and its consequences. In this study, UC-MSCs or ulinastatin was administered intravenously in the rats with burn trauma, and the therapeutic effects of UC-MSCs on the survival of severe burn-induced AKI rats and functional protection of kidney were analyzed. Results showed that UC-MSCs promoted the survival and prevented commitment to apoptosis of resident kidney cells and reduced organ microscopic damage in kidneys after thermal trauma. Thus, our study demonstrates that intravenously delivered UC-MSCs protected the host from death caused by kidney injury subsequent to severe burn, identifying UC-MSCs transplantation may be an attractive candidate for cell-based treatments for burns and induced organ damage.