PARIS - President Denis Sassou Nguesso took power in Congo-Brazzaville in 1979 and has been in office ever since, except for a five-year period.
Congo officials are claiming that 90 percent of those who participated in Sunday's referendum on amending the constitution voted to allow him to continue.
He will join a long list of African leaders reluctant to relinquish power.
Here is a list of Africa's longest-serving leaders:
36 years: Teodoro Obiang Nguema Mbasogo, Equatorial Guinea.
Came to power in a coup on August 3, 1979. He was officially named president on October 12, 1982.
36 years: Jose Eduardo dos Santos, Angola.
Leader of the party which won independence from Portugal in 1975, Dos Santos has been in power since September 20, 1979.
35 years: Robert Mugabe, Zimbabwe.
The only living African leader to have been continuously in power since his country's independence, Mugabe became prime minister in April 1980 and president in 1987.
32 years: Paul Biya, Cameroon.
Came to power on November 6, 1982.
29 years: Yoweri Museveni, Uganda.
Took office in January 1986 after winning the war which ousted the brutal regime of Idi Amin Dada, with help from neighbouring Tanzania.
29 years: King Mswati III, Swaziland.
Acceded to the throne of the tiny southern African kingdom in April 1986, four years after the death of his father.
26 years: Omar al-Bashir, Sudan.
Has ruled since he seized power in a coup in June 1989.
25 years: Idriss Deby, Chad.
Emerged as the leader of the arid north-central African state in December 1990, after the war which ousted the regime of Hissein Habre.
The longest-serving leaders of post-colonial African countries have been:
Emperor King Haile Selassie, who was ousted from power in Ethiopia in 1974 after 44 years.
Muammar Gaddafi of Libya, who ruled his north-African state for almost 42 years after a coup in 1969. Kadhafi was ousted and then killed in 2011 by a rebel movement backed by western warplanes.
Omar Bongo Ondimba, who ruled the west African state of Gabon for more than 41 years until his death in October 2011. He was then succeeded by his son.