The goldfinch's preferred food is small seeds such as those from thistles (the Latin name is from Carduus, a genus of thistles) and teasels, but insects are also taken when feeding young. It also regularly visits bird feeders in winter. They nest in the outer twigs of tall leafy trees, or even in bamboo, laying four to six eggs which hatch in 11–14 days.
In the winter goldfinches group together to form flocks of up to forty birds, occasionally more.
The song is a pleasant silvery twittering. The call is a melodic tickeLIT, and the song is a pleasant tinkling medley of trills and twitters, but always including the trisyllabic call phrase or a teLLIT-teLLIT-teLLIT.
In earlier times, the Goldfinch was kept as a cagebird for its song. Escapes from captivity and deliberate releases have colonised southeastern Australia and New Zealand.
Goldfinches are attracted to back gardens in Europe and North America by birdfeeders containing niger (commercially described as nyjer) seed. This seed of an annual from South Asia is small, and high in oils. Special polycarbonate feeders with small oval slits at which the Goldfinches feed are sometimes used.