He then became Director of the Centre for Medical Imaging in Cotonou in 2002, where he remained until his appointment as Permanent Representative to the UN.
He presented his credentials to the Secretary-General of the United Nations on 8 September 2005, replacing Joel Wassi Adechi.
As Permanent Representative, Idohou sat on the United Nations Security Council in 2005 when Benin held one of the rotating positions.
He was replaced as Permanent Representative by Jean-Marie Ehouzou in 2006.