Introduction: Identifying neuropeptides and understanding their effects are very important in order to understand different mechanisms of the body. Over the past years, there have been extensive studies on the role of neuropeptide B/W system in various physiological processes. Therefore, in the present study, we will investigate the structure, distribution and physiological functions of neuropeptide B and W by reviewing past researches. Search Method: In this regard, articles related to the neuropeptide B and W system and its physiological functions were identified by searching appropriate keywords in reliable databases, and in order to obtain further studies, the reference list of these articles was also checked. Results: Based on the results of past studies, despite the structural similarities and distribution of neuropeptides, there are differences in their physiological roles. It seems that the neuropeptide system plays an important role in regulating food intake, although the effects of neuropeptides have been different from each other. In addition, the role of this system in other physiological functions such as sleep, circadian rhythm, cardiovascular system, emotions, endocrine glands and pain has been proven. Research has shown the importance of the role of neuropeptide W and NPB/W1 receptor in regulating the mentioned functions. Conclusion: The current study has a comprehensive look at the neuropeptide B and W system, from its structure to its various physiological functions, and while presenting data from previous studies, it reveals the missing links in the study of this system, which can be used to determine the direction of future research.