Two series of chloro/p-chloro phenoxy substituted azetidinones were synthesized incorporating benzimidazole moiety. Phthalimide and glycine were reacted to give N-phthalyl acetic acid (1) which was further cyclized to give N-methyl phthalyl benzimidazole (2) on treatment with o-phenylene diamine. Further treatment with chloro sulphonic acid and then with hydrazine hydrate, followed by reaction with different aromatic aldehydes gave the Schiff bases(5a-d). These schiff bases formed when treated with chloro/ p-chlorophenoxy acetyl chloride underwent cyclization to give the azetidinones (7a-d).The chemical structure of the newly synthesized compounds were characterized by elemental analysis, IR , 1H-NMR and Mass spectra. The title compounds were screened for their antimicrobial activity against four bacterial and two fungal strains. The bacterial strains used were Escherichia coli, Alcaligenes faecalis , Pseudomonas aeruginosa and Klebsiella pneumoniae and fungal strains used were Chaetomium globosum and Curvularia lunata . The synthesized compounds were evaluated for qualitative (zone of inhibition) antimicrobial activity by agar cup plate method at three concentrations (500,1000 and 3000ppm). Compound (6b) and (7c) showed good to excellent activity against all the tested strains while others were moderately active.