A series of new cyclic imide: isoindoline-1, 3-dione derivatives were synthesized by condensation of 2-hydrazinyl-2-oxo-N-phenylacetamide and phthalic anhydride. The characterization of synthesized compounds was done by IR, 1H NMR, 13C NMR and mass spectroscopy. All these synthesized compounds were tested for in vitro antimicrobial against various bacterial and fungal strains in N, N-dimethyl formamide and Dimethyl sulfoxide. It is observed that almost all the compounds showed moderate antimicrobial activity and N, N-dimethyl formamide is better solvent than dimethyl sulfoxide.