Sepsis represents a clinical syndrome following an infection and it is characterized by classical signs of systemic inflammatory response syndrome (SIRS): fever or ipothermia, tachycardia, tachipnea, leucocytosis or leucopenia. There may also be symptoms related to a specific infection such as a cough in pneumonia or burning with urination in a kidney infection, and abdominal pain in an intraabdominal sepsis. Common locations for the primary infection include lungs, brain, urinary tract, skin and soft tissues, and mainly abdominal organs. Patients who develop sepsis have an increased risk of complications and death and face higher healthcare costs and longer treatment. The infection is caused most commonly by bacteria, but can also be by fungi, viruses, or parasites. Severe sepsis is sepsis causing poor organ function or insufficient blood flow; septic shock is the situation with ipotension and/or need for high dosage of inotropes or vasopressors and multiple organ failure syndrome is when multiple organ dysfunction or failure is present. Outcomes depend on the severity of disease with the risk of death from sepsis being as high as 30%, severe sepsis as high as 50%, and septic shock as high as 80%. Prevention, early diagnosis, and treatment, both medical (antibiotics) and surgical (source control), together with the prompt intensive care and organ support are crucial to increase survival rate.