The acid-base and hydroelectrolyte balance were evaluated in 116 patients with cirrhosis of the liver divided (a posteriori) into subjects without ascites, those with tractable ascites, and those with intractable ascites. Alterations were much earlier and more frequent in the pre-ascitic stage. A fall in arterial blood O2 tension also proved a poor prognostic factor. The water load test and 24-hr determination of natriuria best reflected the clinical picture and should thus act as pointers to the correct planning of treatment.