Open wounds are a nightmare for the immune system. With the external barrier of the skin breached, the exposed tissues are vulnerable to attack by the hordes of microbes rampant in the external environment. The immune system rallies to the defence of the body by sending in the cells and molecules of the innate immune division which throw themselves into close combat at the front line. The battle can go either way, but in chronic wounds it usually develops into a lengthy stand-off. This article describes the details of the battle looking at the combined defensive forces of the innate and adaptive immune systems.