STACHYSLAVANDULIFOLIAVAHL.FROM LAMIACEAE FAMILY IS FREQUENTLY USED IN IRANIAN TRADITIONAL MEDICINE AS AN ANXIOLYTIC ANDTO TREAT DIARRHEA [1]. NOWADAYS, MEDICINAL PLANTS HAVE RENEWED INTEREST IN THEIR USE AS ALTERNATIVE SOURCE OF ANTIMICROBIAL COMPOUNDS [2] DUE TO PROBLEMS OF THE UNCONTROLLED USE OF SYNTHETIC ANTIBIOTICS [3].IN THIS STUDY, THE METHANOLIC EXTRACT FROM THE AERIAL PARTS OF THE S. LAVENDIFOLIA WAS PREPARED USING THE STANDARD METHODS [4] ANDTHE SOLVENT WAS SUBSEQUENTLY ISOLATEDTHROUGH AROTARY EVAPORATOR APPARATUS. THEREAFTER, THE ANTIBACTERIAL EFFECTS OF THE EXTRACTWERE EXAMINED USING DISK DIFFUSIONMETHOD AND BROTH MICRODILUTION AGAINST DIFFERENT BACTERIA. TO STANDARDIZE OF STUDY, WE USED ANTIBIOGRAM DISKS ALONG WITH ATCCBACTERI. S. LAVENDIFOLIA METHANOLIC EXTRACT EXHIBITED HIGH PROMISING EFFECTS AGAINST SOME HUMAN PATHOGEN BACTERIA STRAINS SUCH AS STAPHYLOCOCCUS AUREUS, ESCHERICHIA COLI, KLEBSIELLA PNEUMONIA, PSEUDOMONAS AERUGINOSA, WITH ZONE INHIBITIONS AND MINIMAL INHIBITORY CONCENTRATION (MIC) VALUES OVER THE RANGE 16-22 MM AND 12.5, 6.25, 12.5 AND 12.5 MG/ML, RESPECTIVELY. IN ADDITION, MINIMAL BACTERICIDAL CONCENTRATION (mbc) VALUES WERE FOUND TO BE 25, 12.5, 25 AND 25 MG/ML, RESPECTIVELY. MOREOVER, BY USING THE DISK DIFFUSION METHOD, ANTIBACTERIAL EFFECTS OF MENTIONED EXTRACT AGAINST E.COLI ATCC 25922 WERE COMPARED WITH AMOXICILLIN AND IMIPENEM. ADDITIONALLY, THE SIGNIFICANT CONSTITUENT COMPONENTS IN ORGANS WERE RESPECTIVELY MYRCENE (41.6%), A-PINENE (L) (33.0%), B-TERPINENE (12.2%), B-PINENE (L) (5.1%), SABINENE (1.3%), A-PHELLANDRENE (1.3%) AND A-YALANGENE (1.1%) ACCOUNTING FOR THE DOMINANCY OF MONOTERPENE HYDROCARBONS OVER OTHER NATURAL PRODUCTS.