In 1979 he was in charge of the press review at Antenne 2 Midi and is commended for reporting of the diamond affair of Jean-Bédel Bokassa, involving Valéry Giscard d'Estaing.

Uncomfortable with the editing of TF1 and opposed to the style of the news show they put on the air in January 1985, which was dramatized and sensationalized, he remained nostalgic for channel A2 and eventually returned to his earlier employ in January 1986 to present the 20 hours alternating with Bernard Rapp He was dropped from the 20 heures news show in July 1987 for having "abused" the chief of police of Paris in the Malik Oussekine case.

However, he remained true to Antenne 2 during his lean years and worked on several broadcasts of reports and debates, which were called Place publique (directed by Serge Moati,[4]), Raison de plus or Géopolis.

During one telethon broadcast, while interviewing Michel Boujenah who was telling incredible stories, Claude Sérillon became known for a very crazy laugh.

On 13 September 1999, true to his reputation for independence, he made an interview without concession of Lionel Jospin then Prime minister,[5] which was severely criticized.

[11] Since 2007, he has co-presented the weekly political show Ôtrement dit broadcast on France Ô and on radio and television at RFO in the Overseas departments with Dominique Roederer.

On 3 January 2013, Claude was named advisor to the President of the Republic, to strengthen the communication service of the Elysee,[3][14] qualified as a spin doctor of l'Élysée by the media.