Following Cameroon's independence, Oyono was a member of the Cameroonian delegation to the United Nations in 1960, when the country was admitted to the UN.
Oyono remained in the post for about a year before Biya instead appointed him as Minister of Town Planning and Housing in 1986.
[9][10][11] Oyono was thought to be a close friend of Paul Biya,[11] and observers attributed his departure from the government to his advanced age and poor health.
[13] After leaving the government, Oyono was thought to retain a great deal of influence as "an unofficial adviser" to Biya.
[16] During a visit to Cameroon by Ban Ki-moon, the Secretary-General of the United Nations, the 80-year-old Oyono died suddenly in Yaoundé on 10 June 2010.
Reportedly Oyono fell ill at the presidential palace after a reception for the Secretary-General; he received immediate medical attention and an ambulance was called, but he quickly died.