Apoptotic cell death plays a critical role in tissue injury and organ dysfunction under a variety of pathologic conditions. The present study was designed to determine whether apoptosis may contribute to post-traumatic cardiac dysfunction, and if so, to investigate the mechanisms involved. Male adult mice were subjected to non-lethal traumatic injury, and cardiomyocyte apoptosis, cardiac function and cardiac production of reactive oxygen/nitrogen species were determined. Modified Noble-Collip drum trauma did not result in circulatory shock, and the 24 hour survival rate was 100%. No direct mechanical traumatic injury was observed in the heart immediately after trauma. However, cardiomyocyte apoptosis gradually increased and reached a maximal level 12 hours after trauma. Significantly, cardiac dysfunction was observed 24 hours after trauma in the isolated perfused heart. This was completely reversed when apoptosis was blocked by administration of a non-selective caspase inhibitor immediately after trauma. In the traumatized hearts, reactive nitrogen species (e.g., nitric oxide) and reactive oxygen species (e.g., superoxide) were both significantly increased, and maximal nitric oxide production preceded maximal apoptosis. Moreover, a highly cytotoxic reactive species, peroxynitrite, was markedly increased in the traumatic heart, and there was a significant positive correlation between cardiac nitrotyrosine content and caspase 3 activity. Our present study demonstrated for the first time that non-lethal traumatic injury caused delayed cell death and that apoptotic cardiomyocyte death contributes to post-trauma organ dysfunction. Anti-apoptotic treatments, such as blockade of reactive/nitrogen/oxygen species generation, may be novel strategies in reducing post-trauma multiple organ failure.