AVOCADO HASS (PERSEA AMERICANA MILL) PEEL EXTRACT (APE) HAS THE POTENTIAL AS A NATURAL INGREDIENT TO SUBSTITUTE FOR CHEMICAL PRESERVATIVES. THE OBJECTIVES OF THIS STUDY WERE TO ASSESS THE PHYTOCHEMICAL COMPOSITION BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY?QUADRUPOLE TIME-OF-FLIGHT MASS/MASS SPECTROMETRY (HPLC-QTOF-MS/MS), TOTAL PHENOLIC CONTENT (TPC), PROANTHOCYANIDIN (PAC) CONTENT, AND ANTIOXIDANT ACTIVITY OF THE APE, THE ORGANIC FRACTION (OF), THE AQUEOUS FRACTION (AF), AND THE ACID-MICROWAVE HYDROLYZED APE (HAPE), ON THE ANTIBACTERIAL ACTIVITY (ABA). THE RESULTS INDICATED THAT APE AND OF CONTAINED (P ? 0.05) A HIGHER PHENOLIC COMPOSITION AND ANTIOXIDANT ACTIVITY THAN AF AND HAPE. THE ABA SPECIFIED THAT PSEUDOMONAS AERUGINOSA AND BACILLUS CEREUS WERE INHIBITED BY ALL THE EXTRACTS (MINIMAL INHIBITORY CONCENTRATION?MIC ? 500 ?G/ML), STAPHYLOCOCCUS AUREUS WAS ONLY SIGNIFICANTLY INHIBITED BY APE (?750 ?G/ML), THE SAME MIC WAS OBSERVED FOR THE OF ON SALMONELLA SPP. AND LISTERIA MONOCYTOGENES. THE HAPE INCREASED THE INHIBITORY EFFICIENCY UP TO 25% ON ESCHERICHIA COLI AND SALMONELLA SPP. (MIC ? 750 ?G/ML), AND 83.34% ON L. MONOCYTOGENES (MIC ? 125 ?G/ML) COMPARED TO APE (MIC ? 750 ?G/ML). ALSO, HAPE INHIBITED THE BIOFILM FORMATION AT THE LOWEST CONCENTRATION (125 ?G/ML); MEANWHILE, THE BIOFILM DISRUPTION SHOWED TO BE CONCENTRATION-TIME-DEPENDENT (P ? 0.05) COMPARED TO AMOXICILLIN. IN CONCLUSION, THE FRACTIONATION AND HYDROLYZATION OF APE IMPROVED THE ABA; THUS, THOSE STRATEGIES ARE USEFUL TO DESIGN NEW ANTIMICROBIAL COMPOUNDS.