During his time in Jamaica, he seems to have encountered Sir Henry Morgan (Sir H.M., aged about 4 5, lean, sallow-coloured, his Eyes a little yellowish . . . much given to drinking and sitting up late.) and made the acquaintance of other adventurers who later sent or brought documents to him to add to his collection of buccaneer narratives and maps,
He later recorded his Caribbean experiences in the two-volume lavishly illustrated A Voyage to the Islands Madera, Barbados, Nieves, S. Christophers and Jamaica. (1707 and 1725).
Albemarle's death in October 1688 did not result in an immediate return to England. Upheavals surrounding the English throne delayed Sloane's departure until March 1689.
After returning to London at the end of May 1689, Sloane spent four years as physician to Albemarle's widow, then set up a successful practice in Bloomsbury, where his patients included many of the most leading figures of the day. He was appointed as head physician at Christ's Hospital, London in November 1694, received a doctor's degree from Oxford in 1701 and was elected to the College of Physicians of Edinburgh four years later.
His professional status is reflected in his appointment as physician-extraordinary to Queen Anne (1712), physician-general to the army (1716), president of the Royal College of Physicians (1719) and further royal appointments under George I and II.
Apart from his medical work, Sloane continued to follow scientific interests, publishing his observations from the West Indies in the Royal Society's Philosophical Transactions as he collated and rationalised the material he had gathered there.