The drug was well absorbed from the intestinal tract, and the bulk of it was excreted in the urine and feces. Biliary excretion was significant, and the existence of enterohepatic circulation was considered likely. After intravenous injection, elimination of radioactivity from the blood and various tissues, except for fat, was rapid for 2 hr, then became slower. Elimination of unchanged drug from the blood was very fast. Repeated oral doses did not changed the excretion and distribution features as compared to a single oral dose. Significant accumulation of radioactivity was not caused by repeated doses of ¹⁴C-labeled perisoxal. Three oxidized metabolites, p-hydroxyperisoxal, m-hydroxyperisoxal and 4-hydroxyperisoxal, were identified. Excretion of hydroxyperisoxals in the urine (free and conjugates) was greater than that of perisoxal itself.