In recent years the field of invertebrate endocrinology has witnessed considerable progress in certain areas while little or no advancement has been made in others. The great majority of work continues to be done with insects. In this brief review attention is focused primarily on three areas of insect endocrinology: intermediary metabolism, osmoregulation, and growth and development. Some comments are made about the intimacy of the neural and endocrine systems of invertebrates. The apparent production of hormones throughout the nervous system of arthropods is noted, and evidence is cited that direct delivery of neurosecretory hormones to target organs may be common.