A series of newer 1,3,4-oxadiazole derivatives containing R-phenyl moiety were synthesized by reacting R-substituted aromatic acids with hydrazine hydrate in presence of various reagents at different reaction conditions. The structural elucidation of these compounds is based on their spectral data (IR, 1HNMR,MS and elemental analysis).All the newly Synthesized 1,3,4-oxadiazole derivatives have been screened for their antibacterial activity against three different strains, namely E. coli, S. aureusand P. aeruginosa, while antifungal activity was determined against three different strains such asC.neoformans, C. albicans andC.glabrata. The investigation of antimicrobialscreening revealed that compounds 4a, 4g, and 4hexhibited excellent activity when compared with the standard drugs.