The crystal structure of the 26 kDa glutathione S-transferase from Schistosoma japonicum (SjGST) was determined at 3 A resolution in the new space group P2(1)2(1)2(1). The structure of orthorhombic SjGST reveals unique features of the ligand-binding site and dimer interface when compared with previously reported structures. SjGST is recognized as the major detoxification enzyme of S. japonicum, a pathogenic helminth causing schistosomiasis. As resistance against the established inhibitor of SjGST, praziquantel, has been reported these results might prove to be valuable for the development of novel drugs.