The group, 350 Otepoti Dunedin, held a Fossil Free Banks Challenge, which called on banks to cut ties with the fossil fuel industry.
Campaigner Claudia Palmer said the group was calling for ethical investment and lending policies from banks.
It wanted to ensure the banks would neither invest in, nor lend to, coal, oil and gas projects.
The idea was to "put pressure on those banks to show them what New Zealanders and their customers want".
Groups in Auckland, Kapiti, Wellington, Nelson and Christchurch also ran events.