From 1968 to 1972 he studied Industrial Psychology at Stellenbosch University, graduating with a Bachelor of Arts (Honours) degree. Du Plessis lodged at the university's Wilgenhof men's residence. Built in 1903, Wilgenhof is not only the oldest university men's residence in South Africa, but also once housed the future Springbok and South African rugby administrator Danie Craven himself – both as a student, and as administrator. Craven was the resident principal of Wilgenhof during the period that Du Plessis lived there.