An estimated 3,000 people have joined an anti-nuclear rally in the French Polynesian capital, Papeete, organised by the ruling pro-independence party.
This followed two marches from the east and west of the city, which met up outside the territorial assembly.
The crew of Japan's Peace Boat, named after the NGO by the same name, also joined the event, which according to correspondents had fewer participants than expected.
France carried out more than 180 nuclear weapons tests in the South Pacific, the last one in 1996.
The assembly's president, Jacqui Drollet, says although the tests are over, nuclear waste has been left behind which will be there for thousands of years to come.
In 2010, France acknowledged for the first time that its tests weren't clean.
It passed a compensation law for test victims, but to date practically all claims have been rejected.