The Department of Plant Science and Biotechnology started as the Department of Botany during the 1962/63 Session at the Zwelling building which it shared with Zoology Department. It was among the original Departments in the Faculty of Sciences as at the 1962/63 Session. The first Head of Department of the then Department of Botany was Prof. H. Z. Naqui, a Plant Pathologist. He held office from the 1962/53 – 1964/65 Sessions. In 1973/74 the Department of Botany was placed under the Faculty of Biological Sciences which came into existence when the Faculty of Science was split into the Faculties of Physical and Biological Sciences.
In 1976/77 Session, the Department came under the re-designated Faculty of Biological and Pharmaceutical Sciences. By 1980/81 Session the Department returned to the Faculty of Biological Sciences when the former twin Faculty of Biological and Pharmaceutical Sciences was split into the Faculties of Biological Sciences and Pharmaceutical Sciences. It has ever remained in the Faculty of Biological Sciences and has now changed to the Department of Plant Science and Biotechnology, in line with global changes in the life sciences, for greater service delivery to the society.