Shelf life in minimally processed foods is mainly reduced by spoilage microorganisms. Many preservation methods have been developed as the application of chemical additives. Nowadays, the tendencies are the use of natural substances as chitosan or plant essential oils as alternative preservants. Chitosan is a biopolymer from natural sources with antimicrobial activity against a wide range of pathogenic and food spoilage microorganisms. Essential oils also have an inhibitory effect. Disk diffusion test in Müller-Hinton agar was made to find the inhibitory effect in vitro of chitosan 1%, essential oil of lemon (EOL) 1% and orange (EOO) 1% against Escherichia coli, Staphylococcus aureus, Salmonella sp. and Saccharomyces cerevisiae. Inhibitory effect on minimally processed mango was evaluated by microbiological analysis for 11 days, every 4 days. EOL showed the greatest inhibition zones (14 mm) for St. aureus, S cerevisiae y S. enteritidis y de 12 mm for E. coli. Combination of chitosan and EOL presented evidence of inhibitory activity in vitro. A decrement in total coliforms microorganisms was observed in all treatments. Total coliforms were found only in the control after the storage was finished. Since the 7th day chitosan and EOL showed inhibition over total coliforms. A bacteriostatic effect against mesophyllic bacteria was observed. Chitosan and EOL treatment showed the biggest differences with the control in the molds and yeast counts (1.5 logarithmic units). Combination of essential oil of lemon and chitosan showed an additive effect. Chitosan and EOL presented the highest biological activity in vitro and in the mango.