Aim: The study designed to evaluate the Geno-protective effect of green tea extract against genotoxicity induced by metronidazole and tinidazole. Methods: Thirty-six mice were used, For each experiment, The animals divided into 6 groups: Group I- Negative control administered distilled water; Group II-Healthy mice treated with metronidazole alone, Group III- Healthy mice treated with tinidazole alone; Group IV- Healthy mice administered green tea extract alone Group V- Healthy mice treated with metronidazole, followed by green tea extract administration, Group VI- Healthy mice treated with tinidazole, followed by administration of green tea extract. Results: treatment with Tinidazole significantly increase total chromosomal aberration (0.185± 0.0039, 0.167±0.0049) as compared to negative control group (0.116±0.004, 0.103±0.004) in bone marrow and spleen cells respectively. In addition results showed significant change in total chromosomal aberration between the groups (II, IV, V) (0.122±0.012, 0.079±0.005, 0.101±0.0077) (0.121±0.005, 0.067±0.002, 0.087±0.004) in bone marrow cells and spleen cells respectively. In addition, the results shown that there are significant changes in total chromosomal aberration between the groups (III, IV, VI) (0.185±0.0039, 0.079±0.005, 0.133±0.0135) (0.167±0.0049, 0.067±0.002, 0.11±0.012) in bone marrow cells and spleen cells respectively. Conclusion: Tinidazole has greater effect than metronidazole on total chromosomal aberration and the aqueous extract of green tea confers Geno-protective effect against the metronidazole or tinidazole induced genotoxicity in mice.