Bacterial translocation is a phenomenon in which live bacteria cross the intestinal barrier. The definition may be broadened to include transmural passage of bacterial cell wall components such as lipopolysaccharide and peptidoglycan polysaccharide. After translocation, bacteria or their products reach the mesenteric lymph nodes. From there, it is possible that enteric bacteria, their cell wall components, or both may disseminate throughout the body, causing sepsis, shock, multisystem organ dysfunction, or death of the host. Bacterial translocation and its complications have been shown clearly to occur in animal models, but its existence and importance in humans has been difficult to ascertain. The purpose of this review is to evaluate the data from studies in humans on the occurrence of bacterial translocation and, more importantly, to evaluate its role as a cause of death in humans. Studies from trauma and intensive care centers often imply that bacterial translocation is a major contributor to sepsis, shock, and multisystem organ failure in humans. However, the data reviewed herein do not support that view clearly. Carefully designed studies are needed to determine the relevance of bacterial translocation in human disease.