Professor Du Plessis serves as a Professor emeritus Faculty of Law at the University of the Free State specialising in Labour Law and Retirement Fund Law.
He is an Advocate of the Supreme Court of South Africa and is a member of the Industrial Law Society (England), the International Pension and Employee Benefits Lawyers Association (IPEBLA), the Pension Lawyers Association of South Africa and SASLAW.
He has published several articles in legal journals; co-author of handbook on Labour Law; delivered papers at Professional and Academic Symposiums.
He is the Chairperson of the Board of Management of UFS Pension Fund and the UFS Provident Fund. And has undertaken research for the Committee of Investigation into a Retirement Provision System for South Africa.