In June 1815 he was appointed Grand Provost of the Gendarmerie (i.e. military police) accompanying the French army in Belgium during the Waterloo Campaign. He was present at Ligny and at the Battle of Waterloo itself, where in the evening of 18 June he was wounded. During the retreat he rode, while bleeding, in the company of Napoleon as far as Charleroi, before proceeding to Beaumont, where he attempted to rally those fleeing and stem the rout. At Maubeuge and Avesnes on the 19th he issued orders to the gendarmes to start arresting the fugitives in an attempt to reconstitute the army and restore discipline. At Laon on 20 June he again met the Emperor, who soon proceeded to Paris, where Radet soon followed, having been granted leave to rest and heal his wounds. While Radet was in Paris Napoleon abdicated for the second time.