More than two-thirds rejected the move in French Guiana
Referendums in two French overseas departments have rejected plans for increased autonomy.
With a 48% turnout, 69.8% in French Guiana voted against the proposal. In Martinique, the margin was greater: 80% voted against, with a 55% turnout.
The votes come a year after violence hit French Caribbean territories, in protests over low wages.
French President Nicolas Sarkozy proposed holding the referendums after visiting Martinique in June.
Voters were asked whether they wanted local government to be given more powers, a change that would make the departments more like autonomous French territories, including New Caledonia in the Pacific Ocean.
The two territories have been departments - giving them the same political status as mainland France - for more than 60 years, and receive considerable financial support from central government.
One voter in Martinique questioned whether the country could cope politically with more autonomy.
"I would like a change, but I don't think we are ready yet. I don't trust the people who lead the regional council, " Jacqueline Manger told the Associated Press news agency.
Guadeloupe, another French overseas department in the region, is also due to hold a referendum on the same issue, but officials say that regional elections in March should be held first.