Barrister Adnan has substantial experience in advising Large project financing in Bangladesh, especially in the energy sector. He has been transaction counsel in most of the mega power plants in the country undertaken in the last few years. He has practiced in corporate and commercial litigation and arbitration, banking and finance advisory work, companies and securities law, public and administrative law, admiralty, shipping matters and taxation for 13 years. Barrister Adnan practiced as member and later managing counsel of the Dhaka Annex of Temple Court Chambers, London for two years. He began his practice as a pupil and then as an associate of Dr. M. Zahir – an authority on company law in Bangladesh.

He has substantial legislative drafting experience. He drafted the proposed Admiralty Rules of the Supreme Court of Bangladesh. He was also one of the counsels on the privatization of the Bangladesh Telegraph and Telephone Board (BTTB) and drafted the Bangladesh Telecom Company Ltd Ordinance, 2008. He was legal adviser to the Bangladesh Medical and Dental Council, the regulatory body for doctors and dentists in Bangladesh for 9 years and a counsel on the panel of lawyers of Grameen Phone Limited, a Telenor group concern and the largest telecom company in Bangladesh. Recently he drafted the Bangladesh Medical and Dental Council Regulations 2012 for the Council. 

He was the author of the Exchanges (Demutualization) Bill, 2012 for the Dhaka Stock Exchange. He regularly advises foreign multi-national companies and FDI projects.
Barrister Adnan has published articles on securities law, international trade law (particularly, documentary credits), constitutional law and admiralty law. Outside of his work as a lawyer, he has been chief executive of the Environmental Development Foundation, a non-profit organization dedicated to preservation of the environment.