Young leaflets can be eaten raw or cooked in small quantities and the uniquely flavoured flowers can be eaten as a garnish.
Tansy was a commonly grown domestic remedy. Mainly used as a vermifuge to expel intestinal worms and, as a stimulant and tonic. Caution should be advised as tansy has some toxicity associated with it.
It is a dye plant, and the leaves and flowers are used to repel insects. Growing and dried herb is said to repel fleas. It is a good addition to the compost heap.