Brass and copper household utensils are a possible source of the gross hepatic copper accumulation characteristic of Indian childhood cirrhosis (ICC). In 107 families with a child with ICC, the use of copper or brass for water storage (97%) and of brass for milk storage (90%) or milk boiling (67%) resembled that of neighbouring village control families. However, the feeding history of 132 children with ICC differed from that of 70 children with other hepatic disorders and 311 children in 2 rural control groups. No child with ICC was exclusively breast-fed whereas 10%, 32%, and 25% of the control children were. Duration of breast-feeding was shorter in children with ICC and animal milk was introduced earlier. 57% were started on animal milk before 3 months of age. The age at introduction of animal milk correlated with the age at presentation with ICC. 66 urban Pune children had a feeding history similar to those with ICC, but in these families brass vessels were not used for milk. Experimentally, milk took up copper from utensils more avidly than water did. The copper concentration in milk samples obtained from ICC households, and those obtained experimentally, would supply a copper intake 6 to 20 times greater than that of the breast-fed infant, and similar to that producing copper toxicosis in the lamb. The hypothesis that early introduction of copper contaminated animal milk is of aetiological importance explains many of the epidemiological features of ICC.