Artemisia scoparia (A. scoparia), perennial herb is indigenous to Korea and has been traditionally used in liver damage. We investigated the effect of the essential oil obtained from A. scoparia on apoptosis of KB cells. Cytotoxicity and cellular DNA content were analyzed by MTT assay and flow cytometry, agarose gel electrophoresis, and Hoechst 33258 staining. The caspase-3 and poly (ADP-ribose) polymerase (PARP) proteins were estimated by Western blotting method. We found that the essential oil induced the apoptosis of the KB cells by concentrations of 0.4 to 0.2 mg/ml which was verified by DNA fragmentation, apoptotic bodies, and the sub-G0/G1 ratio. The essential oil also transient caspase-9 and caspase-3 activity and cleavage of PARP in KB cells for 24 h. The essential oil-induced apoptotic cell death was accompanied by up-regulation of Bax and down-regulation of Bcl-2. In conclusion, we demonstrated that the essential oil of A. scoparia induces apoptosis in KB cells