The present paper reports on toxicokinetics of bromoxynil after oral administration of two different dosages in male and female rats. The concentrations measured in serum proceed with a terminal half life of 20 h. Differences in sex are expressed in MRT- and AUC-values. The simulated concentration course after multiple dosing corresponds essentially to experimental course (male rats). Toxicokinetics studies of liver and kidney show a saturation kinetics in kidney after oral administration of a high dose (100 mg/kg KM) in case female rats.