A retrospective analysis of 22 patients whose ascitic fluid had been analyzed prior to the onset of spontaneous bacterial peritonitis, during infection and/or after treatment of peritonitis revealed that neither the ascitic fluid total protein nor the absolute ascitic fluid glucose changed during the infection or after treatment of the infection although the ascitic fluid/serum glucose ratio did decrease (p < 0.001) with infection. The ascitic fluid lactate dehydrogenase increased significantly (p < 0.05) during infection compared to the baseline value. Contrary to the typical findings in infected body fluids, the total protein content and absolute glucose content of “spontaneously” infected ascitic fluid do not measurably change.