Three of four family members reported recurrent episodes of gastrointestinal illness while residing in a house in a small northwestern Vermont village. The father and two daughters repeatedly experienced episodes of emesis and abdominal pain after drinking water drawn from their kitchen faucet. One early-morning water sample taken from the family household contained a copper level of 7.8 mg/L, which is above the standard for drinking water (1.0 mg/L). Values for the second daughter's copper in hair analysis (1,200 micrograms/g) and copper in nail analysis (100 micrograms/g) were elevated (normal range 11 to 53 micrograms/g). The household was at the end of a 3/4-in (19.05-mm) copper main, and it is suspected that copper levels increased in water when the water remained stagnant in the main. All symptoms of the family resolved when they stopped drinking water in their home. This is the first report of copper-induced gastrointestinal illness attributable to a public supply of drinking water.