In this investigation, a series of some novel 2-(2-hydroxybenzylideneamino)-5,7-dihydro-4H-thieno[2,3-c]pyran-3-carbonitriles (4a-f) have been synthesized. These substances have all been examined for antibacterial activities against pathogenic strains Listeria monocytogenes 4b, Staphylococcus aureus, Escherichia coli, Salmonella typhi H, Pseudomonas putida, Brucella abortus, Shigella dysenteriae. thype 7, Staphylococcus epidermis, Micrococcus luteus, Bacillus cereus, Enterobacter aerogenes and antifungal activity against Candida albicans. Most of the studied compounds were found effective against bacteria and yeast. Compound 4f exhibited activity against Pseudomonas putida, Brucella abortus, Staphylococcus aureus, Candida albicans and 4c Brucella abortus, Staphylococcus epidermis comparable to standard antibiotics. In addition, the anti-genotoxic activity of these substances was evaluated by a micronucleus (MN) test. Among the synthesized compounds, 4c was found to have the most anti-mutagenic effect against AFB(1). It was also found that different concentrations of these substances suppressed the mutagenic effects of Aflatoxin B-1 (AFB(1)) in the MN test (however 10 mu M is the most effective dose). It seems that the antimutagenic effects of these substances may originate from their antioxidant potency or reaction of the aflatoxine lactone carbonyl functional group.