The following members served as President of the Institute (the Society, prior to July 2013) during the years indicated. Terms of office run from the Annual General Meeting in the first year indicated until the end of the Annual General meeting in the second year indicated. AGMs are typically held in July or August each year.
| 1957- 1963 | J. | Aspinal |
| 1963 – 1964 | A | Hilhorst |
| 1964 | R.T. | Jamieson |
| 1964 – 1965 | M.M. | Muller |
| 1965 – 1966 | P.C. | Pirow |
| 1966 – 1967 | E.S. | Russell |
| 1967 – 1968 | R.C. | Lloyd |
| 1968 – 1969 | W. | Carine |
| 1969 | H.N. | Van der Merwe |
| 1969 – 1970 | H.H. | Knothe |
| 1970 – 1971 | V. | Marting |
| 1971 – 1972 | V.E. | Andries |
| 1972 – 1973 | H.F.B. | Nel |
| 1973 – 1974 | A.O. | Bischoff |
| 1974 – 1975 | G.D. | Van der Veer |
| 1975 – 1977 | J.J | Van Rensburg |
| 1977 – 1978 | N.M. | Duffy |
| 1978 – 1980 | H.W. | Le Roux |
| 1980 – 1981 | D.H. | Edwards |
| 1981 – 1983 | T.C. | Bouwer |
| 1983 – 1985 | G. | Wiechers |
| 1985 – 1987 | E.S.H. | Davies |
| 1987 – 1989 | J.H.K. | Mattison |
| 1989 – 1991 | C.S. | Palmer |
| 1991 – 1993 | P. | Opperman |
| 1993 – 1995 | P.L. | Davies |
| 1995 – 1997 | S.J. | Reynolds |
| 1997 – 1999 | Dr. J. | Miller |
| 1999 – 2001 | P. | Aspinall |
| 2001 – 2003 | E. | Roberg |
| 2003 – 2004 | R.S. | Moodley |
| 2004 – 2008 | Ms. M.C. | De Roche |
| 2008 – 2012 | M.A. | Schofield |
| 2012 – 2014 | Dr. R. | Dagada |
| 2014 – 2015 | W. | Matope |
| 2015 – 2019 | Ms. U. | Exner |
| 2019 – 2021 | T. | Mashegoane |
