A defined mixture of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) was subcutaneously administered to marmoset monkeys (Callithrix jacchus). Concentrations in different tissues were measured 7 days after treatment. High amounts of the applied dose could be detected for the 2,3,7,8-substituted congeners only. For almost all of these compounds highest concentrations were detected in hepatic and adipose tissue, corresponding values in kidney, brain, lung, heart, thymus or testes were clearly lower. © 1990.