The conversion from micro- to macronodular cirrhosis is claimed to be a general phenomenon. In this study, the conversion was quantitated by means of liver needle follow-up biopsies and autopsy in 156 patients followed in a controlled clinical trial of prednisone treatment in cirrhosis. In the initial biopsy, 75 patients were classified as micronodular cirrhosis, and of them, 68 had macronodular cirrhosis at autopsy indicating a conversion ratio of about 0.9 in 10 years. This may overestimate the true conversion ratio slightly since conversion in many cases only was demonstrated at autopsy where the diagnosis of macronodular cirrhosis is made with greater certainty than from a needle biopsy. The median time interval between the diagnosis of micro- and macronodular cirrhosis was 2.25 years which is a maximum estimate of the conversion time due to irregular spacing between biopsies (or biopsy and autopsy). No significant difference was found between the conversion time in females and males. The conversion was faster in patients not drinking alcohol compared to patients drinking alcohol, but the difference was not significant. Prednisone treatment tended to accelerate the conversion, but not significantly.