Although embryonic stem (ES) cell–like induced pluripotent stem (iPS) cells have potential therapeutic applications in humans, they are also useful for creating genetically modified human disease models in nonhuman primates. In this study, we generated common marmoset iPS cells from fetal liver cells via the retrovirus-mediated introduction of six human transcription factors: Oct-3/4, Sox2, Klf4, c-Myc, Nanog, and Lin28. Four to five weeks after introduction, several colonies resembling marmoset ES cells were observed and picked for further expansion in ES cell medium. Eight cell lines were established, and validation analyses of the marmoset iPS cells followed. We detected the expression of ES cell–specific surface markers. Reverse transcription-PCR showed that these iPS cells expressed endogenous Oct-3/4, Sox2, Klf4, c-Myc, Nanog and Lin28 genes, whereas all of the transgenes were silenced. Karyotype analysis showed that two of three iPS cell lines retained a normal karyotype after a 2-month culture. Both embryoid body and teratoma formation showed that marmoset iPS cells had the developmental potential to give rise to differentiated derivatives of all three primary germ layers. In summary, we generated marmoset iPS cells via the transduction of six transcription factors; this provides a powerful preclinical model for studies in regenerative medicine.