The effects of somatostatin, or somatotropin release-inhibiting factor (SRIF), and SRIF analogs in human diseases have been widely investigated to potentially expand the therapeutic applications of commercially available and newly designed compounds belonging to this class of agents. Several preclinical studies and clinical trials have demonstrated the antiproliferative and antisecretory effects of SRIF and its analogs. This review discusses results from studies investigating the secretory activity and cell viability of SRIF analogs, and the potential of new therapeutic applications of these drugs in endocrine diseases and, in particular, as a treatment for endocrine neoplasia.