The metabolic fate of [14C]-labelled 2 and 4-chlorobenzoic acids (2- and 4-CBA) has been determined in the rat following intraperitoneal (i.p.) administration at 100 mg/kg to male rats. The major route of elimination for both 2-and 4-CBA was urine with > 80%, of the dose recovered in the initial 0-24 h after administration. Glycine conjugation was found to be the dominant metabolic fate for both [14C] 2- and 4-CBA however, the position of chloro substitution had a clear effect on the extent of metabolism via this route with ortho substitution reducing the extent of metabolism via this pathway.