Glutathione S-transferase was purified more than 500-fold with a recovery of 50;from the latex of Hevea brasiliensis. The purification steps involved affinity chromatography, ion-exchange chromatography and gel filtration. The moecular weight of the native enzyme was 50 000 Daltons as determined by gel filtration while sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the presence of one type of sub-unit with a molecular weight of 23 000 daltons. Substrate specificity studies revealed the enzyme to have limited specificity. The N-terminal amino acid was determined to be glycine while the isoelectric point of this enzyme was estimated to be 4.3. The enzyme exhibited multiplicity on ion-exchange chromatography which could be abolished if the column was eluted with thiol reagents.