Antibacterial, antifungal activity and MIC values of the acetone, methanol and chloroform extracts of the lichen Bryoria capillaris (Ach.) and its barbatolic acid constituent have been investigated against Gram-positive and Gram-negative bacteria, yeasts and filamentous fungi using disk-diffusion method. Microplate Alamar Blue Assay was also carried out to determine the antitubercular activity. The extracts of lichen were shown considerable antimicrobial effect to tested pathogenic microorganisms. Also, the isolated compound barbatolic acid significantly affected against the infectious pathogen Mycobacterium tuberculosis H37Rv with a MIC value of 31.25 μg/ml. Present study is the first report on antimicrobial activities of barbatolic acid constituent of lichen B. capillaris.