GlutathioneS-transferases (EC ) (GSTs), are a family of multifunctional enzymes present in all living organisms whose main function is the detoxification of electrophilic compounds. GSTs are considered the most prominent detoxifying class II enzymes in helminths. We describehere the characterizationof novel dehydroascorbate reductase and thiol transferase activities that reside in the human parasite Schistosoma mansoni GSTx.