Regulation of cell proliferation is a critical aspect of the development of multicellular organisms. The ocular lens is an excellent model system in which to unravel the mechanisms controlling cell proliferation during development. In recent years, several cell cycle regulators have been shown to be essential for maintaining normal patterns of lens cell proliferation. Additionally, many growth factor signaling pathways and cell adhesion factors have been shown to have the capacity to regulate lens cell proliferation. Given this complexity, understanding the cross talk between these many signaling pathways and how they are coordinated are important directions for the future.