In this study, the geno-toxic and antigeno-toxic properties of the total extracts of four lichen species were investigated by using human lymphocytes. We obtained total extracts from R. farinacea, X parietina, U articulata and U. filipendula lichen species. The results of our studies showed that 5 mu M concentrations of AFB(1) changed the frequencies of micronucleus (MN) and malondialdehyde (MDA) levels, as well as superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GPx) activities. When 5, 10 and 20 mu g/ml concentrations of total extract were added to AFB(1), the frequencies of MN and MDA levels were decreased, and SOD, GSH and GPx levels were increased. Consequently, our findings show that four lichen total extracts have strong antigenotoxic properties against aflatoxin B-1.