Between 1991 and 1993 he was the Associate Dean of the Faculty of Law of the University of Nigeria. In 1992, Prof. Quashigah was a MacArthur Foundation Visiting Scholar at the University of Wisconsin, USA and a Fulbright Scholar at the Harvard Human Rights Program between 2001/ 2002. His teaching and research interests includes Constitutional Law, Human Rights, International Humanitarian Law, Jurisprudence, Governance, Elections Law and Alternative Dispute Resolution. In 2005, he was adjudged and honored as the Best Teacher in the Humanities in the University of Ghana.