The common marmoset (marmoset; Callithrix jacchus) shows anatomical and physiological features that are in common with humans. Establishing induced pluripotent stem cells (iPSCs) from marmosets holds promise for enhancing the utility of the animal model for biomedical and preclinical studies. However, in spite of the presence of some previous reports on marmoset iPSCs, the reprogramming technology in marmosets is still under development. In particular, the efficacy of RNA-based reprogramming has not been thoroughly investigated. In this study, we attempted RNA-based reprogramming for deriving iPSCs from marmoset fibroblasts. Although we failed to derive iPSC colonies from marmoset fibroblasts by using a conventional RNA-based reprogramming method previously validated in human fibroblasts, we succeeded in deriving colony-forming cells with a modified induction medium supplemented with a novel set of small molecules. Importantly, following one-week culture of the colony-forming cells in conventional embryonic stem cell (ESC) medium, we obtained iPSCs which express endogenous pluripotent markers and show a differentiation potential into all three germ layers. Taken together, our results indicate that RNA-based reprogramming, which is valuable for deriving transgene-free iPSCs, is applicable to marmosets. (C) 2019 Elsevier Inc. All rights reserved.