Methods of producing human stem cells are disclosed for parthenogenetically activating human oocytes by manipulation of O.sub.2 tension, including manipulation of Ca.sup.2+ under high O.sub.2 tension and contacting oocytes with serine threonine kinase inhibitors under low O.sub.2 tension, isolating inner cell masses (ICMs) from the activated oocytes, and culturing the cells of the isolated ICMs under high O.sub.2 tension. Moreover, methods are described for the production of stems cells from activated oocytes in the absence of non-human animal products, including the use of human feeder cells/products for culturing ICM/stem cells. Stem cells produced by the disclosed methods are also described.