To understand the pathogenesis of a disease, experimental models are needed. A good experimental model is the one that simulates responses observed in the clinical setting. In recent years, clinical studies have indicated that gender might be a factor that plays a significant role in the outcome of patients with shock, trauma, and sepsis. These observations are now being evaluated in experimental setting. Studies performed in a rodent model of trauma-hemorrhage have concluded that alterations in immune and cardiac functions after trauma-hemorrhage are more markedly depressed in adult males, and ovariectomized and aged females. However, both are maintained in castrated males and in proestrus females. Moreover, the survival rate of proestrus females subjected to sepsis after trauma-hemorrhage is significantly higher than age-matched males or ovariectomized females. Although these observations suggest gender-specific response after trauma-hemorrhage, the mechanisms responsible for gender specificity remain largely unknown. Furthermore, in other injuries such as burn, experimental studies dealing with sexual dimorphism are limited. Therefore, more studies in clinical and experimental settings are required to determine whether gender-specific responses are global across the injuries or are observed in specific injury situations. Studies are also needed to delineate underlying mechanisms responsible for differences between males and females after trauma-hemorrhage. The information gained from the experimental studies will help in designing innovative therapeutic approaches for the treatment of trauma patients. Copyright © 2005 by the Shock Society.