He was a gunnery officer aboard a missile frigate in the Pakistan Navy and qualified to be a logistics officer on a submarine.

At the time of the 1971 war, he was studying in the United States Army Intelligence Center for a joint NATO counter-intelligence training program [1][2][3] He was made the deputy director general of newly created DGFI under Lieutenant General Ziaur Rahman's supervision.

He was a deputy martial law administrator during the regime of President Hussain Muhammad Ershad and the Minister for Communication and Shipping.

[4] Upon the death of naval chief Rear Admiral Mahbub Ali Khan on 6 August 1984, Sultan Ahmed became the chief of Bangladesh navy.

He continued to serve as the naval chief till 14 August 1990, few months before Ershad resigned as the president of the country.