Concentrations of taurine were measured in a number of tissues from rhesus monkeys fed a taurine-free human infant formula with or without taurine supplementation for 6 mo and 12 mo. At 6 mo, tissue taurine content was significantly greater in the monkeys supplemented with taurine, but by 12 mo, there was no longer a significant difference. Activities of enzymes involved in taurine biosynthesis did not differ between the groups at any age. There was no difference in biliary bile acid class composition between the groups, but the proportion of bile acids conjugated with taurine reflected the tissue taurine content (i.e., was significantly greater in monkeys supplemented with taurine at 6 mo). This difference also disappeared by 12 mo. These results indicate that dependence on dietary sources of taurine persists for at least the first 6 mo but declines by 12 mo. Thus, dietary taurine content is reflected in the tissue taurine content and proportion of bile acids conjugated with taurine in infant rhesus monkeys at least until 6 mo of age, but the body taurine status in animals 12 mo old or older is not an indicator of previous status.