Born in Aberdeen, James Matthews Duncan was educated at Aberdeen Grammar School. He obtained an MA from Marischal College, before going on to study medicine in Aberdeen and Edinburgh. In 1846 he obtained an MD from Aberdeen and a year later he was made a Licentiate of the Royal College of Surgeons of Edinburgh. He was appointed junior assistant to Professor James Young Simpson and took part in the early experiments with chloroform. He became a Fellow of the College in 1851 and in 1861 he was appointed Physician to the Royal Infirmary ward for diseases of women. In 1877 he was invited to occupy the Chair of Midwifery in the Medical School of St Bartholomew's Hospital, London, and to become Obstetric Physician to the Hospital. At that time Duncan was established as leading obstetrician in Scotland and it was greatly regretted by his colleagues and patients when he accepted.