Nganda was born to minor Sebeki (chief) Iguye Nganda and his third wife. Nganda studied in Kampala, Uganda and in Liverpool. In the UK he met and married a Lovian girl who became his favorite wife; Nganda had other wives later on but left them. He returned to Tagog in 1954 and served as a colonial administrator, as head of the census department from 1957 to 1959. He was elected to the Assembly of Members in 1960 and in 1961 became a member of Sir Benjamin Banki's cabinet upon independence.
Nganda was a close confidant of President Banki and in 1964 he was appointed Prime Minister when Banki declared a republic. Nganda, though, was fearful of Banki's socialist policies and secretly conspired with the army to stage a coup. In July 1967 Banki was removed from office and Nganda was made president.
Nganda, though, quickly consolidated his power by appointing friends and family members to government posts. Millions of dollars worth were squandered by him and his family, and Nganda reportedly wanted to build an artificial island near Gogat in the shape of his profile. The military, worried about all this decided to act and on 1 January 1971 they deposed Nganda; the president somehow knew what was going on and had managed to flee with his family on a private plane with several million Tagogese pounds to Kenya.
Nganda was tried in absentia and sentenced to death in a show trial in 1972. By then Nganda had escaped to Lovia, his wife's home country, where he resides today.
With Helen Nganda-Rogers, his first wife, he had two sons, David (born in 1951) and another 1956. With his second wife he had three daughters in the 1960s and with his third wife he had a son, Milton Obote Nganda, in 1965. Milton was grooming his son David to be his successor and briefly served in minor posts in 1970 and 1971. But, David joined the conspirators of the 1st January plot of 1971 against his father, but was later tortured and killed for his family ties.