Prostaglandins are found diffusely throughout the central nervous tissue, which is endowed with complete systems capable of synthesizing and metabolizing distinct prostaglandin types. In addition, these compounds are found in the cerebrospinal fluid. Prostaglandin actions are varied and include effects on behavior, regulation of food intake, body temperature, and cardioregulatory and motor functions. These compounds probably function as modulators or mediators of humoral and other stimuli to neurons. The mechanisms have not been precisely defined. Evidence suggests that prostaglandins are functionally related to the adenyl cyclase-cyclic adenosine monophosphate system. This report deals with literature surveyed up to April 1973.