Despite intensive research, a treatment for diabetic patients that completely restores normoglycemia for an indefinite period of time remains elusive. Although islet transplantation temporarily confers normoglycemia to patients, the lack of a renewable source of insulin-producing β cells hampers the use of this treatment option. Although significant hurdles remain, recent advances in stem cell biology indicate that generation of fully matured β cells from uncommitted progenitor cells, including human embryonic stem cells and induced pluripotent stem cells derived from somatic cell populations, is becoming an achievable goal.