Grietjie is Professor in Accounting, Economic and Business History in the Department of Accountancy at the University of Johannesburg. She has published widely on insurance and banking history as well as the history of South African conglomerates, with special reference to the rise of Afrikaner business in South Africa. Her research includes the development of the accountancy profession in South Africa in comparative perspective with other Commonwealth countries; the reconstruction of colonial Gross Domestic Product for the second half of the nineteenth century South African colonies; big business groups, family businesses in South Africa, globalisation of African emerging market business, and the history and development of African business. She has published two monographs, chapters in 23 books, 72 peer reviewed articles and delivered 82 international and national conference papers. She published two books:
- Verhoef, G (2017) The History of Business in Africa. Complex discontinuity to emerging markets. Studies in Economic History. Springer.
- Verhoef, G (2018) The power of your life. The Sanlam century of insurance empowerment, 1918–2018. Oxford: Oxford University Press.