At the outbreak of the Franco-Prussian War, Ducrot was tasked with overseeing the deployment of French forces due to his familiarity with the terrain near Wissembourg.

His unsupported division was surprised and defeated by a large force of Prussians and Bavarians at the Battle of Wissembourg.

At the Battle of Sedan on 1 September 1870, he succeeded to command of the French army when Marshal MacMahon was wounded early in the morning.

")Ducrot ordered the army to withdraw, but then General de Wimpffen presented a commission authorizing him to succeed MacMahon.

With de Wimpffen having insisted on command, Ducrot refused to accept responsibility for signing the articles of surrender and was imprisoned by the Prussians.