The concept of an integrated bidirectionally regulated neuroendocrine-immune adaptive response to stress has strong experimental support. The quality and intensity of this coordinated response to stress varies depending upon age, gender, reproductive status, and other genetically determined factors as well as the types and magnitudes of environmental challenges. These factors and dysfunctional communication between the nervous, endocrine, and immune systems appear to contribute to the development of autoimmune diseases in the Lewis and BB rats, the OS chicken, and the NOD, MRL, NZB, NZW, and NZB/NZW F1 mice. Neuroendocrine-immune dysfunction also contributes to the pathogenesis of human autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, thyroid diseases, and others. This review highlights these concepts. It includes discussions on various aspects of the stress response, the hypothalamic-pituitary-adrenal and -gonadal axes, corticotropin releasing hormone, luteinizing hormone releasing hormone, interleukin-1 and -6, corticosteroids, estrogens, testosterone, dehydroepiandrosterone, growth hormone, prolactin, and thyroid hormone. The role of the nervous and endocrine systems in regulating thymopoiesis and T cell development is also emphasized.