The tissue distribution and excretion of bromoxynil were studied in male rat. A single oral dose of 12.9 mg bromoxynil /kg body weight was administered to rat. Rats were killed after 0.5, 1, 3, 6, 12, 24, 48, 72, 120, and 168 h. At termination of 24 h, 2.80 and 0.01 % of the compound were excreted in the urine and feces, respectively. By 168 h the urinary and fecal cumulative excretion rose to 21.90 and 14.11%, respectively. Bromoxynil was readily absorbed and subsequently distributed throughout the body. Bromoxynil concentrations increased in serum as the time passed reaching a peak concentration of 256.09ng/ml at 48 h following administration. Peak concentrations of bromoxynil were also reached at 48 h in liver (345.15ng/g) and brain (67.85ng/g). However, bromoxynil level in kidneys reached peak concentration (647.19ng/g) at 24 h after dosing. Bromoxynil begin to decline in the tissues as time passed to reach 10.67, 27.86 and 22.31ng/g(ml) in serum, liver and kidneys, respectively. In case of brain, the lowest amount of bromoxynil (23.01ng/g) reached at 120 h and disappeared after 168 h following administration. Bromoxynilwas disappeared biexponentially from serum, liver, kidneys and brain. The terminal half-life t__ampersandsignfrac12; of bromoxynil was 48.0, 62.0, 60.0, and 34.8 h for the serum, liver, brain and kidneys, respectively. This indicates that there was no tendency for bromoxynil to retain in rat tissue.