Md. Rezaul Islam embarked on his legal career after obtaining an LLM from the Islamic University, Bangladesh. He honed his skills as an Apprentice Advocate in the Supreme Court of Bangladesh under the mentorship of N. H. Khandkar, Senior Advocate. During this tenure from February 1, 1995, to July 18, 2005, he gained extensive experience in various legal proceedings, including Civil and Criminal Jurisdiction, Writ Petitions, and matters related to Human and Fundamental Rights.

Elevated to the esteemed position of Deputy Attorney General for Bangladesh on June 20, 2007, Md. Rezaul Islam further solidified his expertise in Criminal Appellate Jurisdiction, handling cases involving Death Reference and rigorous imprisonment. Subsequently, he served as Deputy Attorney General until January 6, 2008, advocating in Civil, Criminal, and Writ Jurisdiction, as well as matters concerning Election, Taxation, and Human Rights.

As an Assistant Attorney General for Bangladesh from July 18, 2005, to June 19, 2007, Md. Rezaul Islam demonstrated his proficiency in various legal spheres, including Civil, Criminal, and Writ Jurisdiction, Election matters, and Human Rights cases. Additionally, he contributed to office administration, legal opinions, and training courses, ensuring efficient departmental operations.

Md. Rezaul Islam's diverse work experience also extends to roles in the Administrative Tribunal, where he provided legal assistance to government employees seeking to establish their rights. He managed office operations, developed course curricula, and conducted training sessions on various branches of law, human rights, and socio-economic development.

In addition to his legal practice, Md. Rezaul Islam has served as an Examiner for the National University, a Guest Speaker, and a Lecturer at institutions like Northern University Bangladesh and Darul Ihsan University Bangladesh. Fluent in both Bengali and English, he is an active member of prestigious legal associations and societies, including the Bangladesh Supreme Court Bar Association and the Crime Prevention Foundation. As the founder of the Law Consortium and a faculty member at the Department of Law, Northern University Bangladesh, Md. Rezaul Islam continues to shape the legal landscape with his profound knowledge and unwavering commitment to justice.