Alpha amanitin and phalloidin are powerful hepatotoxins that belong to the main classes of toxins namely, amatoxins and phallotoxins, isolated from the deadly poisonous mushroom Amanita phalloides. It is well known that disruptions of antioxidant enzyme defense that include superoxide dismutase (SOD), catalase, glutathione peroxidase lead to generation of reactive oxygen species, followed by increase in the products of lipid peroxidation. Our previous studies showed that alpha amanitin and phalloidin could inhibit catalase activity. These generated the interest to study the in vitro behaviour of both toxins on SOD activity using spectrophotometry. Our result showed some slight increase of SOD after incubation of the enzyme and toxins. Superoxide anion scavenging activity (SSA) of alpha amanitin and phalloidin was also studied. It was established that both toxins, like the enzyme, exhibit SSA activity. It was obvious that at our experimental conditions alpha amanitin and phalloidin behaved as antioxidants.