When the fellowship of the Royal College of Surgeons was established by royal charter in 1843, Quain was one of those selected for the honour. He was admitted on 11 December 1843 and he was elected a Fellow of the Royal Society on 29 February 1844. He became a member of the council of the College of Surgeons in 1854, was a member of the court of examiners in 1865, and chairman of the board of examiners in midwifery in 1867. He was elected president of the college in 1868, and in the following year delivered the Hunterian oration. From 1870 to 1876 he represented the Royal College of Surgeons of England in the General Council of Education and Registration, and at the time of his death was one of Queen Victoria's surgeons-extraordinary. He died on 15 September 1887, and is buried at Finchley.