He was appointed chief of the army's intelligence section (Deuxième Bureau, service de renseignement militaire) in 1895.

The following year Picquart discovered that the memorandum ("bordereau") used to convict Captain Alfred Dreyfus, had actually been the work of Major Ferdinand Walsin Esterhazy.

[2] After the trial of Émile Zola for publishing his 1898 open letter J'Accuse…!, Picquart was himself accused of forging the note that had convinced him of Esterhazy's guilt.

However, the exoneration of Dreyfus in 1906 also absolved Picquart, who was, by an act of the French Chamber of Deputies, promoted to brigadier general.

[7] While still a serving army officer, Picquart died on 19 January 1914 in Amiens from injuries sustained in a fall from a horse while he was riding in Picardy.

[8] Richard Dreyfuss portrayed Picquart in the 1991 made-for-cable drama Prisoner of Honor, directed by Ken Russell which chronicled the Dreyfus Affair.