Reduction of the level of reduced glutathione is one of the mechanisms by which the herbicide paraquat may exert its toxic manifestations. The objective of the present study was to determine the efficacy of an in situ inducer of glutathione, L-2 oxothiazolidine-4-carboxylate, in affording protection against paraquat-mediated pulmonary damage. Male Wistar rats injected with a LD90 dose of paraquat were given varying doses of OTC through gavage to study its effect on survival. The reversal in paraquat-mediated alterations in various biochemical parameters, including those related to the status of glutathione in the tissue, were also studied. The study demonstrated that oral supplementation of OTC to rats receiving paraquat effectively attenuated the paraquat-mediated biochemical changes. The results suggest that OTC may protect rats against paraquat-mediated pulmonary damage.