In Paris, signs accused President Nicolas Sarkozy of "xenophobia" and the "politics of the pillory," Radio France Internationale reported. The demonstrations were organized by a coalition of trade unions and left-wing political groups.
Thousands of Roma, the people formerly known as gypsies, have moved to France, Italy and other Western European countries since Eastern Europe joined the European Union. Almost 1,000 have been returned to Romania and Bulgaria from France since July, when Sarkozy announced a policy of paying them to move.
In Paris, large groups of Roma participated in the march, joined by a group of celebrities who arrived at the starting point in a double-decker bus. They included English-born singer and actress Jane Birkin, singer-songwriter Jeanne Cherhal and director Agnes Jaoui.
Mayor Bertrand Delanoe and Eva Joly, a likely presidential candidate in 2012, also marched.
The largest provincial demonstration was in Angers, in the Loire Valley, where 2,000 people participated.