Serial liver biopsy changes have been reviewed in 30 patients with Indian childhood cirrhosis (ICC) who were randomly allocated to receive treatment with penicillamine in a dose of 20 mg/kg/day, 10 of whom also received prednisolone, and five receiving placebo. The latter died within 185 (mean, 149) days of starting treatment. Nine receiving penicillamine died within 540 (mean, 338) days, but the remainder are well 5.1-9.3 years after commencing treatment. Initial biopsies showed severe hepatocellular injury, pericellular fibrosis, inflammatory infiltration, and orcein-staining granules. Second biopsies taken within 6 months of starting penicillamine usually showed persistence of inflammation and an increase in nodularity with thick and thin active septae. Subsequently the appearances were of an inactive micronodular cirrhosis, with reduction in septal inflammatory infiltrate, hepatocellular injury, and intensity of orcein staining. This further improved to a stage of incomplete fibrous septae. The last liver biopsies at 6-60 months (in 21 survivors) showed almost normal histology in four, incomplete fibrous septae in five, and inactive micronodular cirrhosis with thin septae in 12. Mean liver copper concentrations decreased from 1,407 (SEM, 121) micrograms/g at presentation to 925 (183), 317 (100), and 127 (35) at 6, 6-18, and > 18 months after starting treatment. By contrast, a second biopsy taken in the 6 months after diagnosis in placebo-treated children showed persistence of ICC with increase in inflammation, fibrosis, and orcein staining.