Three of the four children of two unrelated German families fell ill in the first year of life with severe hepatopathy leading to death in two of the children so far, after a progressive clinical course and severe hepatic failure. Laboratory and morphological investigations revealed a high concentration of copper in the liver and to a lesser degree in the kidneys and other organs. The liver architecture was severely altered by micronodular cirrhosis with toxic liver cell damage similar to that found in Indian childhood cirrhosis. Epidemiologically, copper intoxication of the drinking water was verified. The drinking water was obtained from wells via copper pipes. The copper content of the drinking water went as high as 3400 micrograms/l in the two families while water taken directly from the well showed normal content but had lowered pH (6.2). Both parents were clinically healthy, as was an older son who had not been exposed to copper intoxication during the first nine months of his life. Therefore, copper intoxication during the perinatal period appears to be a prerequisite for manifestation of the disease.