Objective(s) Aim of the present study was to screen the antibacterial activities of some medicinal plants extracts traditionally used in Azarbaijan area (Iran). Materials and Methods Thirty-six extracts obtained from different parts of ten plants including Tanacetum balsamita L. (Copmositae), Muscari caucasicum Baker (Hyacinthaceae), Equisetum arvense L. (Equisetaceae), Achillea millefollum L. (Copmositae), Stachys fruticulosa M. Bieb. (Labiatae), Stachys schtschegleevii Sons. ex, Grossh. (Labiatae), Salvia sahendica Boiss & Buhse (Labiatae), Phlomis caucasica Rech. f. (Labiatae), Etchium italicum L. (Boraginaceae) and Thalictrum minus L. (Ranunculaceae) from north-west Iran with traditional medicinal use were examined for their antibacterial activities against some Gram-negative strains such as Escherichia coli, Pseudomonas aeruginosa, Salmonella paratyphi and Serratia marcescens, also, Gram-positive strains of Staphylococcus aureus, Micrococcus luteus, Staph. epidermidis, Streptococcus pneumoniae and Bacillus cereus. The filter paper disc diffusion method as well as broth serial dilution technique were applied to screen the antibacterial efficacy of the extracts and determination of minimum inhibitory values. Results Results indicated that the majority of tested plant extracts had antibacterial activity at least against one of the selected bacteria, with the exception of Muscari caucasicum. Methanol extract of the aerial part of Thalictrum minus L. (Ranunculaceae) showed the most potent antibacterial activity against Staph. aureus with MIC value of ۰.۳۱۲۵ mg/ml. Conclusion The results of this study show that most of the studied plants are potentially a good source of antimicrobial agents and support the traditional applications of some of the tested plants.