OBJECTIVE To review the historical evolution and rationale for the development of new techniques of cardiopulmonary resuscitation (CPR). METHODS English-language studies published after 1960 were identified by computer and manual search using MEDLINE and Index Medicus. Historical references were obtained through a HISTLINE search. Additional information was acquired from personal files and bibliographies of existing literature. METHODS Critical review with emphasis on study size, methods, and reproducibility of results. RESULTS Survival after in-hospital cardiac arrest and institution of CPR is approximately 10% to 15%. Investigation of the physiology of blood flow during CPR has led to the conclusion that flow may occur because of direct cardiac compression or thoracic pump forces. Based on these observations, several new techniques of CPR have been introduced. Interposed abdominal compression, pneumatic vest, and active compression-decompression resuscitation have been shown to improve cardiopulmonary hemodynamics in animal models and humans after cardiac arrest. Only interposed abdominal compression CPR has been shown to improve long-term survival in human subjects after in-hospital cardiac arrest. Although these techniques have shown promising results in animal studies and a limited number of clinical trials, none has gained widespread use. CONCLUSIONS Improved methods of CPR are now available. Selective use of CPR in the hospital and community training in the use of these new adjunctive techniques should have the greatest impact on improved survival after sudden cardiac arrest.