Continuation of the spermatogenic process throughout life relies on proper regulation of selfrenewal and differentiation in spermatogonial stem cells. Mouse spermatogonial stem cells can be cultured with established methods; however, human spermatogonial stem cells are not well understood. Recent reports have shown that adult cells can be reprogrammed to pluripotency if specific genes are delivered and almost established assay. These cells are called iPS (induced pluripotent stem) cells. In addition, it has been reported that pluripotent stem cells can be generated from adult human testes. Stem cell science has progressed remarkably quickly over the last 5 years. Future research into stem cells may reveal the mechanisms underlying male infertility and allow for patient-specific treatments. In this review, we provide an overview of the current understanding of human spermatogonial stem cells and pluripotent stem cells from adult human testes.