A comparative study of the iron-clearing properties of subcutaneously administered desferrioxamine and parabactin is presented. The evaluation was performed in both a non-iron-overloaded bile-duct cannulated rat and an iron-loaded Cebus monkey model. Parabactin was superior to desferrioxamine in both the rodent and the primate. Unlike desferrioxamine, nearly all of the parabactin-induced iron clearance occurred in the bile. This study represents an evaluation of the iron- clearing properties of parabactin, a hexacoordinate catecholamide siderophore.