Essential oils of the three Aromatic plants growing in Egypt; anise(Pimpinella anisum), fennel (Foeniculumvulgare), and spearmint (Menthaspicata) as natural products were examined concerning their chemicalconstituents, antimicrobial and antioxidant activities. Essential oils wereextracted by hydro-distillation method and were analyzed using Gaschromatography/mass spectrometry technique. GC/MS analysis of theessential oils revealed the percentage of major/main components in eachvolatile oil, which was greatly different among all examined oils. Antioxidantactivities of the essential oils were evaluated using the DPPH radicalscavenging assays. Essential oil of Spearmint was more effective antioxidantthan those of fennel and anise. Antimicrobial activities of each oil were tested against some pathogenic bacteria (Bacillus cereus, Pseudomonasaeruginosa, Salmonella Typhimurium, Escherichia coli enterotoxigenic andStenotrophomonas maltophilia) and non-pathogenic bacteria (Bacillus lichneformis, Escherichia coli JM109, E. coli JM109 DE3, E. coli JM109 DE3BL21 PLsS) as indicator strains  . All tested were used at four differentconcentrations (50, 100, 200 and 500 μl/ml) using agar dilution method. The minimum inhibitory concentration (MIC) for each volatile oil was determined.The antibiotic susceptibility test was performed against the test organisms bydisc diffusion method. All tested essential oils were used at concentrations of 70μl/well (diameter 6 mm) in Muller Hinton agar medium. Results showed thatall tested essential oils exhibited markedly antibacterial effect against alltested organisms except forP. aeruginosa which was not affected by volatileoils from anise and fennel. Spearmint oil showing the highest inhibitoryactivity, it was observed for all tested concentrations, while anise oil wasinhibitory against six bacterial members and fennel oil demonstrated thelowest inhibitory effect on bacterial growth. However,Stenotrophomonasmaltophiliashowed less sensitivity towards essential oil extracts. Present dataunderpin the great potential of anise, fennel and spearmint essential oils as biological weapons against various bacterial pathogens from Gram-negativeand Gram-positive bacteria.