Triallate isotopically labeled with 14C and 13C in the C-l allylic carbon position was administered orally to male and female Sprague-Dawley rats at dose levels of 5 and 500 mg/kg of body weight. Most of the dose was rapidly eliminated within 72 h after administration, and dose recoveries averaged 92% and 96 % for the low-dose and high-dose animals, respectively. Approximately 42-52 % of the dose was excreted via the urine and 33-46% via the feces. Expired 14C02 accounted for approximately 4% of the dose, while the residual carcass at sacrifice contained approximately 2%. Radioactivity in blood was associated principally with hemoglobin. Kinetics for whole-body elimination of radioactivity were consistent with a two-compartment open model. The half-life of the a phase varied from 5.9 to 22.8 h, and that of the ß phase from 171 to 265 h.