 Islam joined Mitford Hospital and then Dhaka Medical College as an associate professor in 1958, and Chittagong Medical College as a professor in 1962.With Nuffield scholarship, he worked as visiting professor in London during 1963–1964.He was the founder and director of the Institute of Postgraduate Medicine Research (IPGMR) which is later renamed to Bangabandhu Sheikh Mujib Medical University (BSMMU) for 24 years.