This study was undertaken to determine the cobalt intake in food and milk, and the excretion of cobalt in the urine and feces of young college women living in the home management house at the North Texas State College and consuming a self-selected diet. Cobalt as a trace inorganic element has long been recognized according to Martin (1945) as a nutritional essential in ruminants in whom cobalt deficiency is a typical anemia. For that reason emphasis has been placed upon studies with ruminants, since it seems logical to use a species for which cobalt is known to be essential.