Once ensconced back in Sydney, Jamison proved to be a diligent and capable medical practitioner. He was hampered, however, by a perpetual paucity of surgical supplies and assistants, about which he complained frequently to the authorities. Nonetheless, in 1804, he was able to lead a small medical team which performed the colony's first successful vaccination of children against smallpox. He published Australia's first medical paper, "General Observations on the Smallpox", as a result of this experience. Another of Jamison's innovations occurred in 1808, when he and two colleagues undertook a formal examination of the medical competence of William Redfern, who was put forward by the gubernatorial authorities in Sydney as a person fit to perform surgery in the colony. This set a precedent whereby those wishing to practice medicine in New South Wales would first have to pass a test of their qualifications.