Background: The increased resistance of foodborne pathogens to antimicrobials requires the identification of novel antimicrobials with the ability to inhibit bacterial activity and display no toxicity in ready-to-eat salads such as avocado dip. Purpose: The purpose of this study was to determine the effect of antimicrobials (chitosan, mastic oil, and citric acid) on the viability of Salmonella spp., Escherichia coli O157:H7, and L. monocytogenes (inoculated) in avocado dip kept at 4 and10 oC for 7 days. Methodology: This is an experimental laboratory-based study that was carried out in the SIMIR laboratories. This study aimed to evaluate the effect of different antimicrobials (chitosan (CH) 0.5%, 1%, mastic oil (M) 0.2%, 0.4%, citric acid (CA) 0.15%, 0.3%, and combined treatments, on Salmonella spp., Escherichia coli O157: 7, and L. monocytogenes in the avocado dip at day 0, 1, 3, 5, and 7, at both temperature 4 oC and 10 oC. The study assessed the microbiological growth, chemical activity such as pH and proximate analysis, as well as the sensory evaluation. Results: In avocado dip, at all storage temperatures and periods, Salmonella spp., E. coli O157:H7, and L. monocytogenes growth increased in the absence of antimicrobials. In avocado dip with chitosan 1%, Salmonella spp., and E. coli O157:H7, decreased (p <0.05) from 5.14 to 4.81 and from 5.18 to 4.73 log CFU/g, at temperature 4 oC, respectively. Moreover, adding combinations of citric acid, chitosan, and mastic oil including CACH (CA0.3% + CH1%), CAM (CA0.3% + M0.4%), CHM (CH1%+ M0.4%) and CACHM (CA0.3% + CH1% + M0.4%) to the avocado dip caused a significant reduction in the microbial growth. E. coli O157:H7dropped from 5.14 to 4.82 log CFU/g and Salmonella spp. dropped from 5.18 to 4.60 log CFU/g in samples stored at temperature 4 oC (p<0.05). On the other hand, bacteria growth increased despite adding different antimicrobials at a temperature of 10 oC. In addition, adding various antimicrobial agents individually and in combination increased L. monocytoge