Achillea millefolium Linn. (Asteraceae) is a perennial herb, commonly known as ‘yarrow’ or ‘milfoil’. It occurs mainly in Asia, Europe and USA and blooms from June to September. The plant has a folkloric reputation as an analgesic, antihaemorrhagic, antihelmintic, antimicrobial, antipyretic, antiphlogistic, antiseptic, astringent, carminative, diaphoretic, diuretic, emmenagogue and stimulant. It is used traditionally for curing arthritis, cancer, colic, headache, heartburn, hypertension, hyperglycaemia, inflammations, hepatobiliary and congestive respiratory disorders. Achillea millefolium is known to contain achilleine, achillicin, achillin, achilletine, apigenin, artemitin, austricin, azulene, balchanolide, betoni-cine, butyric acid, casticin, chamazulene, cineole, caffeic acid, dulcitol, furfural, formic acid, humulene, leucodin, limonene, luteolin, millefin, millefolide, quercetin, rutin, b-sitosterol, sabinene, sesquiterpenes, succinic acid, tannin, terpineol, chlorogenic acid, essen-tial oil, mandelic acid, pyrocatechol, salicylic acid, stachydrine, undecylenic acid, camphor, isoborneol and p-cymene. The plant is reported to possess antispasmodic, hepatoprotective, antiinflammatory, antispermatogenic, antiulcer, anti-nociceptive and mosquito repelling properties. This investigation describes the hypotensive, cardio suppressant, vasodilatory and bronchodilatory activities of the aqueous–methanol extract of Achillea millefolium in order to rationalize its medicinal use in hyper-excitable diseases of the cardiovascular and respiratory systems.