A new series of 2-phenyl-3-(6-aryl[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl)-4H-4-chromenone 10(a-j) has been synthesized from 3-(4-amino-5-sulfanyl-4H-1,2,4-triazol-3-yl)-2-phenyl-4H-4-chromenone 9. All newly synthesized compounds were screened for their in vitro antibacterial activities against bacterial strains of Bacillus subtilis, Micrococcus luteus, Proteus mirabilis, and Escherichia coli. The activity of compounds containing 2-chloropheny (10b), 4-chlorophenyl (10c) and 4-methoxyphenyl (10f) are nearly equal to that of standard drug. The compound with 4-hydroxyphenyl (10e) showed significant activity against B. subtilis and M. luteus. Compound 10a and 10g did not show any antibacterial activity against P. mirabilis and E. coli at test concentration.