Embryonic stem cells (ESCs) can be an inexhaustible source of islet cells for transplantation. Previously published protocols have been characterized by low differentiation efficiency. In this study, we developed a scalable system for the growth and differentiation of hESCs towards pancreatic islets. Our results showed that hESCs can be grown on microcarriers to a larger scale and directed to differentiate into pancreatic progenitor endoderm cells. This culture system would represent an economical differentiation protocol that can be scaled-up to meet the demand in islet transplantation.