The generation of induced pluripotent stem (iPS) cells from mouse and human somatic cells by expression of defined transcription factors (Oct4, Sox2, c-Myc, Klf4, Nanog and Lin28) is a powerful tool for conducting basic research and investigating the potential of these cells for replacement therapies. In our laboratory, iPS cells have been generated from adult mouse neural stem cells (NSCs) by ectopic expression of either Oct4 alone (one factor; 1F) or Oct4 plus Klf4 (two factors; 2F). Successful reprogramming of mouse NSCs by 1F or 2F depends on endogenous expression of Sox2, Klf4 and c-Myc. Direct reprogramming of somatic stem cells to 1F or 2F iPS cells avoids expression of the oncogenes Klf4 and c-Myc and, hence, the development of tumors in chimeras and offspring derived from these cells. Here we present a detailed protocol for the derivation of NSCs from adult mouse brain (which takes 4 weeks), and generation of 1F (4-5 weeks) or 2F iPS cells (2-3 weeks) from adult mouse NSCs.