Chetsanga was born in Murewa, Zimbabwe on 22 August 1935,  and was baptised in 1948. In his youth, he was educated at Nhowe Mission, and went on to study at University of California, Berkeley where he received his BSc in 1965. Chetsanga also studied for a period at Pepperdine University. In 1969, he received his MSc and PhD in biochemistry and molecular biology from University of Toronto before becoming a post doctoral fellow at Harvard University between 1969 and 1972. Between 1972 and 1983 he became a professor at the University of Michigan, then in 1983 he left to become the senior lecturer in Biochemistry for University of Zimbabwe. In 1990, President Robert Mugabe awarded him President’s Award for Distinguished Contribution to Science and Technology.  Has also awarded the Order of the Star of Zimbabwe. He is presently the vice chancellor at Zimbabwe Ezekiel Guti University.
In 2004, when the Zimbabwe Academy of Sciences was formed, Chetsanga was appointed the first president of the academy. Chetsanga advocated the use of genetically modified food sources as a possible solution for food shortages in Africa in 2020.