Several lichen species have been used for medicinal purposes throughout the ages, and they were reported to be effective in the treatment of different disorders including tuberculosis, hemorrhoids, ulcer, dysentery and cancer. It is revealed that they may be easily accessible sources of natural drugs that could be used as a possible food supplement or in pharmaceutical industry after their safety evaluations. However, so far, the nature and/or biological roles of plenty of lichenes have not been elucidated exactly. The aim of this study was to investigate the genetic and oxidative effects of water extracts of three different lichen species; Hypogymnia physodes, Ramalina polymorpha and Usnea florida in cultured human blood cells (n = 5) for the first time. All lichen species were collected from the Erzurum and Artvin provinces (in Turkey) during August 2010. The lichen extracts were added into culture tubes at various concentrations (0 to 2000 mg/L). Chromosome aberrations (CA) and micronucleus (MN) tests were used for genotoxic influences estimation. In addition, biochemical parameters (total antioxidant capacity (TAC) and total oxidative stress (TOS)) were examined to determine oxidative effects. In our in-vitro test systems, it was observed that all tested lichen extracts had no mutagenic effects on human lymphocytes. Furthermore, these extracts exhibited antioxidant properties due to the type of lichen species added to the cultures. In conclusion, these lichens can be a new resource of therapeutics as recognized in this study with their non-mutagenic and antioxidant features.