Open AccessA Schiff base, (E)-ethyl-4-(2-oxoacenaphthylen-1(2H)-ylideneamino)benzoate, (E4AB) had been synthesized in good yield by the acid-catalyzed condensation reaction of acenaphthenequinone and ethyl-4-aminobenzoate in methanolic solution. The synthesized compound was elucidated by elemental analysis (CHN), FTIR, 1H-NMR, 13C-NMR and single crystal X-ray diffraction. E4AB crystallized in the monoclinic crystal system with space group P21/c, Z = 4, V = 1569.3(2) Å3 and unit cell parameters a = 9.1589(8) , b = 21.2003(17)Å, c =8.4502(7) &197, β= 106.972(2)°. The crystal structure of the compound is stabilized by intermolecular C-H···O hydrogen bonds and weak intermolecular π···π interactions. The title compound had been tested for the antimicrobial activity against Bacillus subtilis (B. subtilis), Enterobacter and Fusarium oxysporum f. sp. Cubense (Foc) by disc-diffusion method. E4AB is relatively active against Foc which is a pathogen that cause Wilt disease (also well known as Panama disease) in banana plantation.