Miss France 2004 has been stripped of her title for six months after posing for Playboy.
Miss France is allowed to reveal only so much flesh
The head of the committee that runs the contest said she was "dismayed and appalled" by the half-naked photos of Laetitia Bleger in the magazine.
Competition rules mean that Miss France winners can lose their titles if they accept modelling work either partially or fully nude.
Miss France 1983 lost hers after posing as a pin-up for Paris Match magazine.
A statement from the Miss France committee said: "Laetitia Bleger infringed on the rule forbidding the national winner from making herself available for licentious shots - either partially or fully nude."
"We can't let this go," Miss France committee president Genevieve de Fontenay told AFP news agency before the decision was reached.
"Miss France winners have a status to uphold and they know it."
Rules state that winners are barred from engaging in "licentious" behaviour for six years after winning the title.
Miss Bleger was elected at the end of 2003 and was succeeded by the current holder, Cindy Fabre, last December.