Cameron was called to the Bar at the Inner Temple in 1963, but moved to the Faculty of Advocates in 1966. He served as an Advocate Depute from 1972 to 1975, Standing Junior Counsel to the Department of Energy from 1976 to 1979 and Standing Junior Counsel to the Scottish Development Department from 1978 to 1979. He was appointed Queen's Counsel in 1979, and the same year became Director of Faculty Services Limited, the services branch of the Faculty of Advocates, and was its Chairman from 1983 to 1989. He was Legal Chairman of the Pensions Appeal Tribunals from 1979 to 1992, serving in addition as President of the Tribunal from 1985. He was elected Vice-Dean of the Faculty of Advocates in 1983, serving until his appointment to the Bench.