Much progress has been made in the recognition of factors involved in the pathogenesis of the abnormal regulation of extracellular fluid volume in cirrhosis. It is now well established that cirrhosis induces modifications in the activity of several systemic vasoactive factors which then play a major role in the development of renal dysfunction and the formation of ascites and edema. It is also evident that intrarenal factors participate in the pathogenesis of these abnormalities. Nevertheless, the available information is still limited. The link between the diseased liver and the disturbances in the vasoactive systems is not completely known but much evidence suggests that it consists of a circulatory dysfunction that affects mainly the arterial circulation and is characterized by an inability to maintain an effective arterial blood volume within normal limits. Research on the mechanisms of this circulatory dysfunction may yield clues that will help in the design of more pathophysiologically oriented therapeutic approaches to the management of ascites.