This study was carried out to investigate the effect of gamma-irradiation at doses of 0, 5, and 10 kGy on the essential oil constituents of clove and cinnamon; evaluate the efficacy of the extraction of essential oils from irradiated clove and cinnamon as an antimicrobial agent. Results showed that the main components of clove essential oils were eugenol (75.71%) and eugenol acetate (9.73%). The major components of cinnamon essential oils were cinnamaldehyde (75.55%). Gamma irradiation enhanced the antioxidant activity of essential oils. However, irradiation at a dose of 10 kGy was the best treatment for the antioxidant activity of clove and cinnamon essential oils. Essential oils of clove and cinnamon were tested for their antibacterial activity against four strains of S. aureus, E. coli, B. cereus, and P. aeruginosa. Results revealed that each oil tested had a growth-inhibiting impact on the microorganisms under study. Gamma irradiation at a dosage of 10 kGy was more effective against microorganisms.