Recent reports demonstrated the presence of primitive endogenous stem cells circulating within adult cat, dog, sheep, goat, pig, cow, and horse peripheral blood. The current study was undertaken to determine whether similar primitive stem cells could be isolated from the peripheral blood of adult humans. Adult humans had their blood withdrawn following the guidelines of Mercer University School of Medicine and the Medical Center of Central Georgia Institutional Review Boards. The blood was obtained by venipuncture and processed to obtain primitive stem cells. Cells were identified and counted using 0.4% Trypan blue inclusion/exclusion analysis and stained with carcinoembryonic antigen-cell adhesion molecule-1 (CEA-CAM-1) antibody. Totipotent stem cells are both trypan blue and CEA-CAM-1 positive and <2.0 microns in size; transitional-totipotent/pluripotent stem cells are both trypan blue and CEA-CAM-1 positive & negative and >2.0 to <6.0 microns in size; and pluripotent stem cells are both trypan blue and CEA-CAM-1 negative and 6-8 microns in size. The results show that TSCs, Tr-TSC/PSCs, and PSCs are circulating within the peripheral blood of adult humans. Studies are ongoing to address their functional significance during maintenance and healing.