In an effort to establish new candidates with improved antibacterial activities, we reported here the synthesis and in vitro antibacterial evaluation of various series of 2-substituted-3a,4,9,9a-tetrahydro-4,9-benzeno-benz[f]isoindole-1,3-diones: 4-acetyl-phenyl 2, 2,2-dibromoacetylphenyl 3, benzimidazole 4, acetylbenzimidazole 5, aminophenyl 6, acetamide 7, naphthalene 8, disulfide 9, mercaptophenyl 10, hydroxyphenyl 11, phenyl ester 12, triazole 13, benzothiophene 14, benzothiazole 15 phenylazo 16a, b and aminomethane 17 derivatives. The newly synthesized compounds were characterized by (IR, (1)H NMR, (13)C NMR and mass spectrum studies). Representative compounds of the synthesized products were established and evaluated as antibacterial agents.