The present study was conducted to investigate the antimicrobial activity of rosemary and black cumin essential oils against different isolates of microorganisms including two bacteria strains: gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli) as well as two fungus strains (Aspergillus niger and Aspergillus flavus) and one yeast strain (Saccharomyces cerevisiae). Four concentrations of rosemary and black cumin essential oils (5, 10, 15, or 20 µl /ml) were examined against all tested strains of microorganisms by the agar diffusion method. The results showed that all various concentrations of rosemary and black cumin essential oils possess a significant inhibitory effect on the microorganisms strains used in this study. Rosemary is significantly the most effective essential oil against all tested strains of microorganisms compared to black cumin essential oil. The higher concentration of the essential oil has the greatest effect on growth inhibition compared to other concentrations. Depending on the findings of this study, it can be said that the essential oils of rosemary and black cumin have a greater and wider range of antimicrobial activity against several food-borne bacteria, and the crude extract can be used to find biological active items that may act as a starting point for the creation of new antimicrobial compounds. So, it can be recommended to use these essential oils as a source of potential of the active components in food preservatives.