Sepsis has been around since the dawn of time, having been described for more than 2000 years, although clinical definitions are recent. The consensus sepsis definitions have permitted worldwide epidemiological studies of sepsis to be conducted. We now recognize the common nature of sepsis and the consistency of its disease - particularly severe sepsis and septic shock. The incidence of sepsis, severe sepsis and septic shock continues to increase, and although Gram-positive bacterial pathogens remain the most common cause of sepsis, fungal organisms are increasing rapidly. We have made progress over the past half-century in identifying and treating patients with sepsis, and decreasing fatality rates reflect this progress. However, owing to the increasing incidence of sepsis, the number of people who die each year continues to increase. The mortality with sepsis, particularly related to treating organ dysfunction, remains a priority to clinicians worldwide and is deserving of greater public health attention.