Silver ions and Nano silver particles have a great importance as they used as root canal sealers due to their antimicrobial properties. However biocompatibility and satisfactory physico-chemical properties should be achieved to directly contact the root canal sealers with the surrounding tissues. This study aimed to compare the cytotoxicity and genotoxicity of silver-zeolite with silver nanoparticles. MRC-5 cell line was used as an in vitro model. The cell viability was assessed using MTT cytotoxicity assay. Genotoxicity was tested by alkaline single cell gel electrophoresis (comet assay) for measuring DNA damage. Each material was tested in different concentrations (100mg/ml, 50mg/ml, 25mg/ml, 12.5mg/ml, and 6.25mg/ml). The results showed that silver zeolite has lower cytotoxic effect than silver nanoparticles among all different concentrations used in the study. Also the results showed unaccepted cytotoxicity levels for silver nanoparticles on concentrations of 100mg/ml and 50mg/ml. Data obtained from the Comet assay indicated that both silver nanoparticles and silver zeolite causes DNA damage with no significant difference between the two treated groups