The aim of this study is to investigate the effects of the storax balsam, which is a kind of sweet gum obtained from the Liquidambar orientalis Mill trees, on cell viability, cytotoxicity and genotoxicity in human lymphocyte in vitro. We studied the genotoxic effects of the extract of storax balsam (SE) using sister chromatid exchange (SCE) test system. Also the cytotoxic and inhibitory effects on cell proliferation of SE were evaluated using lactate dehydrogenase (LDH) assay and cell proliferation (WST-1) assay. The SCE frequency was increased when the cells were treated with 1.6 and 4.0 µg/mL SE concentrations (p < 0.05). Moreover, treatment of the cells with the same concentrations significantly depleted the cell number at 24th and 48th hours and elevated the LDH levels (p < 0.05) at 48th hour. These results suggest that SE can be used as an alternative antibacterial and antipathogenic agent due to its cytotoxic and genotoxic effects.