It is expected that the incorporation of OEO into fishgelatin–chitosan films suggests the probability not only of giv-ing antimicrobial activity, but also enhancing the physicochemicalattributes. To our knowledge, no data is accessible about the incor-poration of OEO in biocomposite films based on fish gelatin andchitosan.Hence, this work was undertaken to evaluation of oreganoessential oil effect, in different proportions, on the properties ofbiocomposite films. The characterizations included water barrierability, mechanical behavior, optical properties, microstructural,and surface morphology. The antimicrobial properties of the filmsagainst gram-positive bacteria (Staphylococcus aureus and Listeriamonocytogenes) and gram-negative bacteria (Salmonella enteritidisand Escherichia coli) were also assessed.