Abstract The essential oil obtained from aerial parts of Baccharis articulata (Lam.) Pers. from Rio Grande do Sul, Southern Brazil, was analyzed by GC, GC/MS, and chiral phase gas chromatography (CPGC). Twenty-nine compounds representing ca 86.1 % of the oil were identified. The main compounds in the oil were β-pinene (39.0%), cisâ-guaiene (9.8%), γ-muurolene (5.8%), limonene (4.8%), αâpinene (4.5%), αâgurjunene (4.4%) and spathulenol (4.2%). The antimicrobial activity of the oil was evaluated against seven microorganisms using the broth microdilution method. The oil displayed antimicrobial activity against Gram-positive and Gram-negative microorganisms (MIC=2.5 mg/mL).