The article is devoted to classification of sepsis. Two classifications are compared: the Russian one, developed in A.V. Vishnevsky Institute of Surgery (phase I--the initial one or toxemia, phase 2--septicemia; 3--septicopyemia), and the American one, accepted in 1991 in Chicago which singles out three forms of sepsis (sepsis, severe sepsis or sepsis-syndrome, and septic shock). Both classifications are thoroughly analysed and it is stated that there is no principal disagreement in the definition of phases of the course and description of clinical stages of sepsis. The necessity for universal classification of sepsis is emphasized.