A series of 3-(5-phenyl-1,3,4-oxadiazole-2-yl)-2-(substituted styryl)-quinazoline-4(3H)-ones 3(ah) were synthesized by reacting 2-methyl-3-(5-phenyl-1,3,4-oxadiazole-2-yl)-quinazoline-4(3H)- one 2 and substituted benzaldehydes in glacial acetic acid. 2-methyl-3-(5-phenyl-1,3,4- oxadiazole-2-yl)-quinazoline-4(3H)one 2 was obtained by refluxing 2-methylbenzoxazin-4(3H)- one with the 2-amino-5-phenyl-1,3,4-oxadiazole 1. 2-Amino-5-phenyl-1,3,4-oxadiazole 1 was prepared by oxidative cyclization of benzaldehyde semicarbazone and bromine in the presence of glacial acetic acid. All the compounds were screened for antibacterial activity by using cup plate method. Out of these compounds unsubstituted styryl compounds showed significant activity.