In 1850 he was elected a Fellow of the Royal College of Physicians of Edinburgh; and a year or two later was appointed physician and pathologist to the Royal Infirmary of Edinburgh (RIE). During his time at the RIE he was a lecturer at the Edinburgh Extramural School of Medicine. In 1862 he accepted an invitation to take the professorship of medicine in the University of Glasgow, together with the post of physician to the Western Infirmary. In the following year much attention was directed in Glasgow to the insanitary state of the city; and Dr. Gairdner, at considerable pecuniary sacrifice, undertook the duties of medical officer of health, which he discharged for ten years in such a manner as brought about a total change in the conditions which he found existing. From this time forward he devoted himself to the duties of his professorship and to his increasing consulting practice.
