The development of the neuroendocrine hypothalamus has been studied using a variety of neuroanatomical and molecular techniques. Here, the major findings that mold our understanding of hypothalamic development are reviewed. The rat hypothalamus is generated predominantly from the third ventricular neuroepithelium in a "lateral early to medial late" pattern dictated perhaps by the medially receding third ventricle. Neuroendocrine neurons seem to exhibit a delayed migrational strategy, showing relatively early birthdates, although they are located in the latest-generated, periventricular nuclei. Several homeobox genes seem to play a role in hypothalamic development, and gene knockout experiments implicate a number of genes of importance in the generation of the neuroendocrine cell type.