According to the cancer stem cell theory, only a rare subpopulation of cells, called “cancer stem cell”, have the ability to sustain cancer growth, and all the other cancer cells have a limited growth potential or no growth potential at all. In various cancers, including head and neck squamous cell carcinomas（HNSCC）, such cells have been identified and prospectively isolated. The current progress on cancer stem cells in HNSCC, such as CD44 positive cells, aldehyde dehydrogenase positive cells, side population cells and octamer4/nanog/CD133 positive cells, was discussed in this article.
