Abstract An oil of Calamintha nepeta (L.) Savi ssp. glandulosa (Req.) P. W. Ball obtained by hydrodistillation was analyzed by GC and GC/MS and 36 constituents were identified (98.4%). The main constituents in the oil were pulegone (37.5%), menthone (17,6%), piperitenone (15.0%) and piperitone (10.2%). The antimicrobial activity of the oil was screened against Aspergillus niger, Escherichia coli, Staphylococcus aureus, Salmonella enteritidis, Bacillus subtilis and Pseudomonas aeruginosa. The microorganisms were found to be susceptible to the oil