Tissue concentration and elimination and urinary excretion were followed after intravenous injection of C-14-ethion in 12 goats. Tissue levels were determined in two goats after 8 hr and on each of days 1, 3, 7, 14 and 28 after exposure. During the four-week period plasma and all tissues examined (liver, kidney, fat, muscle, lung, heart and brain) had detectable C-14-residues, the highest values being found in liver, kidney and fat. Elimination of C-14-residues was faster in the first 3 days than in the later part of the experiment, where the elimination half-life for most tissues was approximately 2 weeks. During the first two weeks after exposure, 77% of the administered dose was eliminated in urine (55%) and faeces (22%). TLC of urine collected over the first 15 hr after exposure showed at least 8 bands of metabolites, five of which accounted for about two thirds of the dose excreted in urine.