DK Poison started his amateur career on in Accra. He is one of many boxers spawned by Bukom, a suburb in the heart of the city populated by the Ga people. Many top Ghanaian boxers such as Roy Ankrah, Azuma Nelson and Ike Quartey are products of Bukom.
David Kotei turned professional under trainer Attuquaye Clottey. His first professional bout was on February 5, 1966 in Accra when he outpointed his opponent over six rounds. Although he fought once in neighbouring Togo in 1967, all his subsequent fights through to 1971 were all in Ghana. In 1972 however, he fought as much as seven times in Australia, winning five and losing two.
He won the African featherweight title on February 2, 1974 when he knocked out Tahar Ben Hassen in the first round of a scheduled 15 round fight in Tunis, Tunisia. Later on December 7, 1974, he also won the Commonwealth featherweight title with a technical knockout over Evans Armstrong, a British boxer in round 10 of a scheduled 15 rounds bout. This victory gave him an opportunity to go for the World Boxing Council version of the world title. On September 20, 1975, in The Forum, Inglewood, California, United States, he beat Rubén Olivares by split points decision after 15 rounds to become the first Ghanaian world boxing champion.
He relinquished the African and Commonwealth titles following this victory. The Ghana government gave him an estate house at Teshie-Nungua, an Accra suburb in honour of these achievements in boxing. He however lost the title in his third defence on November 6, 1976 by unanimous points decision to Danny "Little Red" Lopez in a fierce fight in Accra, Ghana.He is married with three daughters.He also defeated Fuku Yama in Japan.
DK Poison was never the same again after this defeat. He failed in 1978 to regain either the world or commonwealth featherweight titles. His last professional bout was in 1989 when he lost an African lightweight title fight.
David Kotey has lived a relatively modest and quiet life after retirement. He has gone through marital and financial difficulties and reportedly has some grievances about how his purse was disbursed during his boxing years. He is married with three daughters. He also defeated Fuku Yama in Japan.