Isolation and characterization of leaf volatiles in Anemopsis californica (Nutt.) Hook. and Arn. (A. californica) was performed using steam distillation, solid-phase microextraction, and supercritical fluid extraction. Thirty-eight compounds were detected and identified by gas chromatography; elemicin was the major component of the leaf volatiles. While the composition of the leaf volatiles varied with method of extraction, alpha-pinene, sabinene, beta-phellandrene, 1,8-cineole, piperitone, methyl eugenol, (E)-caryophyllene, and elemicin were usually present in readily detectable amounts. Greenhouse-reared clones of a wild population of A. californica had an identical leaf volatile composition with the parent plants. Steam-distilled oil had antimicrobial properties against 3 (Staphylococcus aureus, Streptococcus pneumoniae, and Geotrichim candidum) of 11 microbial species tested. Some of this bioactivity could be accounted for by the alpha-pinene in the oil.