Aflatoxin B1 alone (0.05 mg resp. 0.037 mg/kg/d), copper alone (6.6 mg/kg/d or 200 mg/l drinking water) or a combination of both was administered orally for 6 months to young guinea pigs from the first/second day of life. In the copper group there were no pathomorphological changes. For the aflatoxin B1 group, liver damage was established. In the combined group, liver injury was more frequent and more severe compared to the aflatoxin B1 group and biliary copper excretion was diminished compared with the copper group. Histologically, only the livers of this group exhibited degeneration, atrophy and steatosis of liver cells, inflammatory processes and a more or less prominent fibrosis. For childhood cirrhosis (ICC and ICT) a combined etiology--a liver damaging agent plus elevated alimentary copper--is a plausible hypothesis.