Abstract— Influence of chitosan and Lippia multiflora (Lm) essential oil used singly or combined was studied on postharvest tomato. Chitosan with 89.31% of DDA and solubility in acetic acid at 97.15 % was extracted from shrimp exoskeletons. Three concentrations of chitosan extracted (0.25; 0.5 and 1%) containing or not L. multiflora oil were used on Rhizopus stolonifer growth in vitro and in situ condition. In vitro condition, antifungal activity of the chitosan and Lm oil against R. stolonifer was conducted on agar media inoculated with fungal spores. Coating containing 1% chitosan incorporated with Lm efficiently inhibited fungal proliferation at 100% after 10 days. The antifungal effect of two molecules was effective when they were associated. In situ condition tomatos were coated with different solution. Antifungal effect and chemical parameters (pH and titrable acidity) were evaluated. Combination of Lm and 1% chitosan delayed efficiently R. stolonifer radial growth (2.1 mm) compared to uncoated fruit (70.37 mm) after 10 days of storage. Chitosan at 1% with or not Lm significantly reduced weight loss. Though, pH and total acidity (TA) were not influenced by coating solution.