Forty-seven consecutive patients with chronic lymphocytic leukemia (CLL) followed in the Clinica Medica and the Sezione di Ematologia of Ferrara from January 1966 to June 1979 were classified according to the staging system of Rai and to age, sex and the occurrence of enlarged spleen or liver or both. Analysis of actuarial survival curves revealed the following: 1) the method of staging proposed by Rai was confirmed to be a reliable predictor for prognosis of CLL; 2( neither age nor sex do appear to be prognostic factor; 3) the enlarged liver did not appear to make worse the prognosis of CLL, probably by hepatomegalies due to other aetiologies. Furthermore the bound of peripheral lymphocytosis of 15,000/mm3, also according to other authors, seems to be too high: numerous cases of undoubted CLL with smaller lymphocytosis ae left out of this and other statistics published on CLL.