There has been a spreading attention in the present day to develop environmentally friendly materials such as biodegradable starch films with antimicrobial properties for food protection. Chitosan has exhibited antimicrobial activity against a wide range of microorganisms which provided great potential to be used as a packaging material to prolong the shelf life of food products. The antimicrobial properties of chitosan against some food-borne pathogens were investigated. Chitosan ranging from 2.5 to 10 mg ml^-1 against some pathogenic bacteria (Escherichia coli TISTR 512, Bacillus cereus TISTR 035 Staphylococcus aureus TISTR 746 and Salmonella typhimurium TISTR 1470) and yeast (Candida albicans TISTR 5554) was determined. All tested bacteria could be inhibited by concentration of 10 mg ml^-1 except C. albicans TISTR 5554. Cassava starch/chitosan films incorporated with lemongrass essential oil were examined in addition to its mechanical properties and antimicrobial stability during storage. Total bacteria and fungi counts were low during 12 weeks of storage and tensile strength decreased after 6 months of storage. However, elongation at break showed no significant difference during the storage process. The functional and structural groups of tested films did not change during 6 months of storage confirmed by fourier transform infrared (FTIR) analysis. Overall, these films have been recognized to be beneficial for application due to its stability, antimicrobial property and biodegradable nature.