Neurogenesis has long been recognized as a property of the adult olfactory epithelium. The olfactory epithelium is a pseudo-stratified, columnar epithelium containing three cell compartments: the superficial supporting cells, the medially located sensory neurons, and the basal cells. The basal cells of the olfactory epithelium have traditionally been divided into two categories on the basis of morphology: horizontal basal cells (HBCs) and globose basal cells (GBCs). This chapter discusses, among other things, the regulation of olfactory neurogenesis, and the molecular regulation of olfactory neurogenesis. Regulation of proliferation, differentiation, survival, and death during olfactory neurogenesis requires multiple factors operating in multiple signaling pathways. All cells in epithelium and lamina propria may play roles in maintaining sensory neuron number and survival. The clinical applications of olfactory neurogenesis include transplantation repair of the spinal cord, and olfactory stem cell models of brain diseases.