The acid-base balance from the postoperative day (POD) 1 to POD 3 after cirrhotic liver resection was investigated in relation to operative outcome by conducting a retrospective study on the changes in arterial ketone body ratio (AKBR), which reflects the hepatic mitochondrial redox state, and arterial blood gas analysis. Patients were grouped according to their outcome: hospital death (HD) and or good outcome, the latter group acting as controls (CTR). Metabolic alkalosis developed in a significant number of the CTR patients (p < 0.01), who had high AKBR values. By contrast, metabolic alkalosis did not develop in the HD group, with significantly lower AKBR (p < 0.001), and there was almost normobasemia. There were no significant differences in the need for mechanical respiratory assistance, the amounts of fresh frozen plasma administered, and renal function test results between the two groups on each of 3 postoperative days. These data indicated that the absence of metabolic alkalosis during the early postoperative days reflects disruption of energy metabolism in the remnant liver, and that the apparent normobasemia is a significant indicator of poor prognosis after cirrhotic liver resection.