The groups, including Amnesty International and Human Rights Watch, say at least 86 people have been executed in 2011 in Iran. They say at least eight of those killed last month were political prisoners.
Iranian Nobel laureate Shirin Ebadi joined the call, saying that the "executions may increase if the world is silent."
Wednesday's appeal also included Reporters Without Borders, the International Campaign for Human Rights in Iran, the International Federation for Human Rights and the Iranian League for the Defense of Human Rights. The groups want a moratorium on all executions in Iran.
The Iranian Embassy in Paris said it had no comment.