Abstract The 3, 4-disubstituted-1, 2, 3, 4, 5, 6, 7, 8-octahydroquinazoline-2-thione derivatives were synthesized and characterized by physicochemical and spectral means, and the results of antimicrobial study of these compounds against Staphylococcus aureus, Escherichia coli, and Candida albicans by tube dilution method indicated that 4-(4- chlorophenyl)-3-(4-nitrophenylsulfonyl)-1, 2, 3, 4, 5, 6, 7, 8-octahydroquinazoline-2-thione ...