A simple strategy for the synthesis of the hitherto unreported 3-arylazo-4-phenyl-[1,2,4]triazepino[2,3-H]quinazoline-2,7(1H)-diones is described. Spectral data indicated that the studied compounds exist predominantly in the hydrazone tautomeric form. The antimicrobial activity of the newly synthesized compounds was also evaluated. The results indicated that some of these compounds have moderate activity towards bacteria.