The last years, research focus has moved to immunostimulatory agents in order to restore or increase the functionality of the immune system during sepsis-induced immunoparalysis. Epidemiologic data show that prehospital use of low dose acetylsalicylic acid (ASA) is associated with improved outcome of sepsis. Experimental data indicate that ASA exerts pro-inflammatory effects during systemic inflammation. However, it remains to be determined whether treatment with ASA improves immune function once immunoparalysis has developed and whether prehospital use of low dose ASA prevents the development of immunoparalysis. In the former case, ASA is a potential immunostimulatory therapy that can treat sepsis-induced immunoparalysis. In the latter case, ASA may have a broader indication as an immunomodulating agent. Taken together, ASA might be a promising, cheap, well-known, and globally available agent to reduce the incidence of secondary infections and improve patient outcome in sepsis.