He previously taught at the School of Law, University of New England, at the Faculty of Law, University of New South Wales and at the School of Law, University of Western Sydney. Hossein's teaching areas include real property law, equity and trusts, immigration and refugee law, comparative law and public international law. He has authored and co-edited a number of books and monographs including The Legal Regime of Offshore Oil Rigs in International Law (2001). Hossein has published scholarly articles in leading law journals in Australia, Europe and the United States. He is the co-editor of the Flinders Law Journal and co-rapporteur of the International Law Association Committee on Islamic law and International Law.