The doctors accuse the government of stigmatizing them and object to an accord aimed at reining in excessive fees.
A total of 30 unions and professional organizations have called for a strike in a sector where such action is not common, the French-language AFP news agency reported.
The groups are making various demands.
Surgical procedures are being cancelled and in cases of emergencies patients are being directed to hospitals.
“Hospitals will be completely the same for dealing with the sick,” Health Minister Marisol Touraine insisted.
The 37 public assistance hospitals of Paris (AP-HP) issued a statement saying certain services would be cancelled, “notably surgical interventions”, but emergency operations are assured.
The strike affects 70 percent of private clinics, around 700 facilities, according to the federation of private hospitals (FHP).
At issue is an agreement limiting doctors’ fees signed by three major doctors’ unions, representing generalists and specialists, under pressure from Touraine, the health minister.
“We must at all costs change this accord because it does not take into account the specific nature of surgery and anesthesia,” Philippe Cuq, president of the union of surgeons told Europe 1.
Doctors in these fields receive “supplements”, which Cuq said are different from excessive fees.
If the accord is not changed “in the next three years the system will stop the practice of private surgeons,” he said.
Touraine defended what she called a “good agreement” while saying that her door remained open for dialogue.
She also maintained the government has no intention of restricting the freedom of doctors to practice where they want.
One union, representing hospital anesthetists, said it would not follow the strike, maintaining that would hurt public service for the “demands of the private sector".