The cyanide detoxifying enzyme, rhodanese was extracted from Synodontis schall gills and some physicochemical properties investigated. Activity of the enzyme preparation was assayed by measuring the activity of rhodanese in RU min-1 mg-1. The results revealed that Synodontis schall gills rhodanese had km values for KCN and Na2S2O3 as 22.73±4.12 and 16.67±5.31 respectively. The enzyme had higher affinity for Na2S2O3. Only ammonium sulphate displayed possible sulfur donating property but was less effective than thiosulphate. Synodontis schall gills rhodanese displayed maximum activity at pH 8.0 and 35֠ºC. Synodontis schall gills rhodanese was significantly (p<0.05) inhibited by PbCl2, BaCl2 and HgCl2 in a concentration dependent manner. Gills rhodanese of Synodontis schall was similar in properties to rhodanese extracted from other sources.