Rheum ribes is a perennial herbaceous plant belonging to the Polygonaceae family that grows more on rocky and gravelly slopes in high attitude areas of Levant and Turkey. Rheum ribes is consumed as food and widely used in folk medicine against nausea, constipation and for different diseases including diabetes and hypertension. Unfortunately, the research on Rheum ribes toxicity is insufficient. In our study, the human hepatocellular carcinoma (HepG2) cell line was used in a cytotoxicity evaluation of Rheum ribes water, methanol and chloroform extracts by MTT and NRU tests. Comet assay was used to investigate the genotoxicity potentials of the plant extracts. Our results show that all extracts cause cell death in a concentration dependent manner at 5-50 mg/mL concentrations. The IC50 values are 14.29-31.94 mg/mL by MTT and 21.15-27.66 mg/mL by NRU assay. The highest concentration (25 mg/mL) of methanol extract causes significant DNA damage (8.7-folds). In conclusion, similar to a lot of plants used in folk medicine the risk of Rheum ribesis still unknown. The uncontrolled use of this plant could cause harm to the patients. Our results indicate the possible cyto- and gentoxicity effects of Rheum ribes, these results should elevate concerns about the safety of Rheum ribes and other folk herbs.