in this study, the essential oil of citrus aurantifolia (christm.) swingle was extracted by hydrodistillation and, after chemical characterization, was evaluated for its antimicrobial activity on a representative range of atcc and clinical strains. the chemical composition of the volatile fraction of key lime oil was determined using gas chromatography-mass spectrometry (gc-ms) and gc-flame ionization detection (gc-fid). the antimicrobial activity of the oil was evaluated on a representative range of gram-positive bacteria, gram-negative bacteria and yeasts, including atcc and clinical strains, by the disc diffusion method and the broth microdilution method. the major components of lime essential oil proved to be -pinene (12.6%), limonene (53.8%), -terpinene (16.5%), terpinolene (0.6%), -terpineol (0.4%) and citral (2.5%), which are very likely responsible for the good antimicrobial activity, in particular on gram-positive bacteria (staphylococcus aureus, bacillus subtilis and staphylococcus epidermidis).