Abstract: Background and Objective: Basil leaves (Ocimum sanctum L.) contain fungicidal and antibacterial compounds such as linalool (56.7-60%) which can be applied as a natural preservative for food including wet noodles. The purpose of this study was to determine the appropriate concentration of basil leaf extract that could inhibit the growth of Escherichia coli and Aspergillus niger to increase the shelf life of wet noodles. Materials and Methods: This study ran an experimental method pursued by statistical analysis using 2 experiments with duplication. Each experiment included the determination of the antimicrobial activity of basil extract (0, 25, 50, 75 and 100% of concentration) against E. coli and A. niger by using the agar diffusion method. The next experiment tested antimicrobial activity using the best concentration of basil extract in wet noodles. Results: The results of this study exhibited that a 100% concentration of basil leaf extract could inhibit E. coli and A. niger with inhibition zones of 30.98 and 5.96 mm, respectively. Antimicrobial activities of 100% concentration of basil extract in wet noodles showed the total number of moulds and coliform values were 3.8×109 CFU g–1 and <10 APM/g, respectively, until 3 days after treatment. Thus, the wet noodles treated with basil leaf extract exhibited good flavour and colour. Conclusion: This study concluded that the treatment of basil leaf extract inhibited E. coli and A. niger activities and preserve the quality of wet noodles.