In this minireview we will discuss some evidence suggesting that the immune response is under neuronal regulation. In particular, we will concentrate on the effects that various neuropeptides have on immunity both in vitro and in vivo. Of these,vasoactive intestinal peptide, substance P, somatostatin, and calcitonin gene related peptide will be discussed in detail. In addition, the effects of nerve growth factor on the immune system will be presented. Finally, a possible role for these neuropeptides in various diseases and its clinical relevance will be suggested.