[4] Chowdhury was born on 31 January 1921 to Bengali Muslim zamindar family in the village of Nagbari in Tangail, Mymensingh district, Bengal Presidency (now Bangladesh).

He obtained his master's and law degrees from University of Calcutta in 1942 and after the second world war he completed bar-at-law in London.

On 10 April 1973,[4] he was again elected as President of Bangladesh, and in the same year (December) he resigned and become special envoy for external relations with the rank of a minister.

After Rahman was assassinated, he became the minister for foreign affairs in the cabinet of President Khondaker Mostaq Ahmad in August 1975, a position which he held till 7 November the same year.

[7] Right after the assassination of Sheikh Mujibur Rahman, Abu Sayeed Chowdhury joined the cabinet of the new government as the foreign minister and praised the new president Khondaker Mostaq Ahmad by saying, "President Khondaker Mostaq Ahmad believes in democracy and he wants to restore democratic atmosphere in the country.