The only son of John Rae (1677–1754), a barber-surgeon originally from Stirlingshire, James was born in Edinburgh in 1716.
In October 1776 his fellow surgeons made a determined attempt to found a professorship of surgery in the University of Edinburgh, and to appoint Rae the first professor.
[2] Rae did in Edinburgh what Percivall Pott did in London, in establishing the teaching of clinical surgery.
[5] He established a reputation as a dentist and was "among the first, (if not the first) in Edinburgh to rescue that department from the ignorant and unskilled hands in which it was then placed.
The elder son William joined the Incorporation of Surgeons on 18 July 1777, settled in London, where he married Isabella, sister of Robert Dallas, and died young.
John, the younger brother, was one of the first fellows of the Royal College of Surgeons of Edinburgh, where he was admitted on 14 March 1781.