A novel series of 6-Iodoquinazolin-4-one derivatives were synthesized and evaluated for their antibacterial and antifungal activities against gram negative viz Escherichia coli, P.aeruginosa and gram positive bacteria viz staphylococcus aures, Bacillus subtilis and Bacillus cereus and pathogenic fungi viz Candida albicans and Saccharomyces cerevisiae. Streptomycin and Nystatin used as standard drugs. All the compounds were characterized by physical and spectral data. All the compounds showed potent to moderately potent antimicrobial activity. These compounds can be further exploited to get the potent lead compound. The detailed synthesis and the antimicrobial screening of the new compounds are reported.