abstract the essential oil composition from the aerial parts of artemisia campestris var. glutinosa gay ex bess and artemisia herba-alba asso (asteraceae) of tunisian origin has been studied by gc and gc/ms. the main constituents of the oil from a. campestris collected in benguerdane (south of tunisia) were found to be -pinene (41.0%), p-cymene (9.9%), -terpinene (7.9%), limonene (6.5%), myrcene (4.1%), -phellandrene (3.4%) and a-pinene (3.2%). whereas the oil from a. herba-alba collected in tataouine (south of tunisia) showed, pinocarvone (38.3%), a-copaene (12.18%), limonene (11.0%), isoamyl2-methylbutyrate (19.5%) as major compounds. the mutagenic and antimutagenic activities of the two oils were investigated by the salmonella typhimurium/microsome assay, with and without addition of an extrinsic metabolic activation system. the oils showed no mutagenicity when tested with salmonella typhimurium strains ta98 and ta97. on the other hand, we showed that each oil had antimutagenic activity against the carcinogen benzo (a) pyrene (b[a] p) when tested with ta97 and ta98 assay systems.