To study the metabolism of 14C-deltamethrin in rats.Rats were dosed orally and i.p. with a single dose of 14C-deltamethrin (0.64 mg/Kg) body weight. The required dose was applied daily for 3 days. At the end of the experiment, selected organs, such as liver, kidney, fat, intestine, and blood were excised for radioassay of 14C-content.Deltamethrin was almost eliminated from the body within 1-3 days. The main portion of 14C-residues was extracted from urine (38%, 32%) and feces (20%, 24%) with a little amount remained in various organs.The elimination and distribution of 14C-radioactivity in rats treated orally and intraperitoneally signify that deltamethrin is bioavailable in urine and feces.