cinnamomum verum essential oil and its main component, cinnamaldehyde, were incorporated into nanoemulsions to improve their stability and activity. oil-in-water (o/w) nanoemulsions were prepared using the high-energy ultra-sonication method. cinnamon oil nanoemulsion exhibited a more vigorous dpph radical scavenging activity (ic50 = 1.81 mg/l) than the standard -tocopherol (ic50 = 9.16 mg/l). cinnamaldehyde nanoemulsion exhibited the highest antibacterial action against salmonella typhimurium and staphylococcus aureus (mic = 175 and 150 mg/l, respectively). it was also displayed the highest inhibition against candida albicans (ec50 = 19.92 mg/l). cinnamaldehyde nanoemulsion was the most active against mycelial growth of aspergillus flavus and a. niger (ec50 = 38.20 and 134.80 mg/l, respectively). it also presented the highest activity against spore germination. this study describes antimicrobials and antioxidants based on nanoemulsions made from natural products that can be used to treat microbial infections.