So as to assess the effects of lithium carbonate on peripheral leucocyte levels of hepatic cirrhosis patients, 10 cirrhotic patients were studied with less than 4,500 leukocytes per cubic ml and without contraindications for lithium salts that were administered for three weeks at a dose of 90 mg daily. At the end of each week total peripheral leukocytes, differential formula, platelet count and serum lithium concentration determinations were made. In the basal stage, total leukocyte average was 3,400 +/- 527 (X +/- DE) and granulocyte average was 2,090 +/- 341. After the first week of lithium treatment a significant increase was observed in total leukocyte and granulocyte levels whose averages at the end of the third week of treatment were 4,800 +/- 1,052 (p less than 0.01) and 3,694 +/- 1,003 (p less than 0.001) respectively. There was no correlation between the magnitude of leukocyte increase and serum lithium levels obtained that ranged from 0.28 and 1.32 mEq/l. Three patients showed transient gross tremor and two suffered hepatic coma. We can conclude that lithium carbonate increases peripheral leucocytes at the expense of neutrophilia in patients with secondary granulocytopenia and hypersplenism resulting in liver cirrhosis.