In Congo-Brazzaville, he worked as chief medical officer in charge of health and social services at Marien Ngouabi University in Brazzaville and in a similar capacity at the National Electrical Company.
[8] In April 2002, he called for international aid to help thousands of people who had fled their homes in the Pool Region due to violence involving rebel Ninja militia fighters.
[12] Opimbat was then chosen as President of the National Assembly's Foreign Affairs and Cooperation Commission on 24 August 2002.
[17] In the June–August 2007 parliamentary election, Opimbat was the FDN candidate in Mbomo constituency, but in the first round of the election, held on 24 June 2007, he was defeated by Jean Matamaya,[3] the candidate of the Movement for Solidarity and Development (MSD), who won a narrow majority with about 52% of the vote.
[3] As of 2008, Opimbat is a member of the National Coordination of the Rally of the Presidential Majority (RMP), a large coalition of parties supporting President Denis Sassou Nguesso.
[21] After several years of dual leadership alongside Tassoua, Opimbat was elected as the sole President of the FDN at its First Ordinary Congress on 2–3 May 2010.
[23] He was then appointed to the government as Minister of Sports and Physical Education as part of a minor reshuffle on 17 August 2011.
[31] In the July 2017 parliamentary election, he was re-elected to the National Assembly as the PCT candidate in Mbomo, winning the seat in the first round with 95% of the vote.