Moringa oleifera has been famous as a natural medicine due to its rich vitamins, minerals, and flavonoids. However, the study of its effect on Enterococcus faecalis (E. faecalis) is limited. This study analyzes the chemical constituents of the ethanol extract of Moringa leaves using GC-MS and assessing the toxicity against E. faecalis. Moringa oleifera leaves were extracted by ethanol, evaporated, and the concentrated extract was analyzed using GC-MS instruments. The effect of cytotoxic of Moringa oleifera against E. faecalis was investigated by morphological and coagulation cells; also, the toxicity area was evaluated by ImageJ software. The GC-MS Spectrum was confirmed by NIST databased resulted in 17 different compounds including Alpha-butyrolactone, 1,3-cyclopentanedione, Glycerin, Cis-1,2,6-trimethylpiperidine, 1,2-epoxy cyclohexane, benzeneacetaldehyde, Isobutyraldehyde, propylhydrazone, 2-pyrrolidinone, 2-butenamide,2-cyano-3-hydroxy, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 2-trideuteromethoxy-3-methyl pyrazine, Benzeneacetonitrile,4-hydroxy-, 1,2,3,3a,4,8b-hexahydrocyclopenta[b]indole, 1,3,4,5-tetrahydroxy-cyclohexane carboxylic acid, Hexadecanoic acid, n-cbz-beta-alanine, and 3-(2,2-dimethyltetrahydrofuran-3-yl)phenol. These active compounds are involved in the cytotoxicity against E. faecalis. The Moringa oleifera leaves have better toxicity at lower concentrations (12.5% and 6.25%) with 24 hours of incubating.: At least 17 chemical components were detected in the ethanol extract of Moringa oleifera leaves with quinic acid, glycerol, and DDMP as the most abundant compound. They probably affect the toxicity of E. faecalis cells.