The aim of this study is to investigate for the first time in vitro antimicrobial and antimutagenic activities of Schiff bases included the azomethine group. Antimutagenic activity was evaluated by micronucleus (MN) assay. These group have been examined for antibacterial activity against pathogenic strains, Staphylococcus aureus, Escherichia coli, Salmonella typhi H, Brucella abortus, Micrococcus luteus, Bacillus cereus, Pseudomonas aeroginosa and antifungal activity against Candida albicans and Saccharomyces cerevisiae. The results of MN showed that Schiff bases ((E)-N-(4-chlorophenyl)-1-(5-nitrothiophen-2-yl)methanimine ; (E)-N-(2,4-dichlorophenyl)-1-(5-nitrothiophen-2-yl) methanimine) different concentrations decreased the toxic effects of Aflatoxin B1. Especially, high concentration (20μM) of (E)-N-(4-chlorophenyl)-1-(5-nitrothiophen-2-yl)methanimine (compound 1) has strong antimutagenic activity. In our in vitro test systems, it was observed that Schiff bases had antimutagenic effects on human lymphocytes. On the other hand these compounds were also found to possess antimicrobial activity against some test bacteria and yeast. The antimicrobial test results of these Schiff bases included the azomethine group exhibited better activity than some known antibiotics. In particular, Compound 1 were more potent bactericides than all of the substances synthesized. In conclusion, this Schiff bases included the azomethine group can be use pharmacy industries as recognized with their noncytotoxic, antimicrobial and antimutagenic features.