The report is a review of current knowledge of the distribution of copper in the environment and living things. Metabolism and the effects of copper in the biosphere are also considered. Copper compounds are common and widely distributed in nature. They are also extensively mined, processed and redistributed by man. Copper is an essential element in plant and animal nutrition. It is closely related to iron, sulfur and molybdenum in animal metabolism. Requirements differ in relation to the nutritional state of these other elements. In plants copper toxicity is infrequent and usually results from soil contamination due to human activities. Deficiency in plants is fairly common, and may require supplementation for crops. In animals both deficiency and toxicity are infrequent except in ruminants. Human copper poisoning occurs rarely in industry, as a cause of food poisoning, resulting from some medical treatments, and from genetic defects in metabolism. Copper levels found in food, water and air have not been found to be injurious.