Embryonic stem cells (ESCs) can self renew and retain the potential to differentiate into each of the cell types within the body. During experimental reprogramming, many of the features of ESCs can be acquired by differentiated target cells. One of these is the unusual cell division cycle that characterizes ESCs in which the Gap (G) phases are short and DNA Synthesis (S) phase predominates. Growing evidence has suggested that this atypical cell-cycle structure may be important for maintaining pluripotency and for enhancing pluripotent conversion. Here, we review current knowledge of cell-cycle regulation in ESCs and outline how this unique cell-cycle structure might contribute to successful reprogramming.