Willem Ten Rhijne, son of Israel Ten Rhijne and his second wife, Anna Peters, received his schooling in Deventer and from about 1664 to 1666 studied medicine at the Hoogeschool (University) of Franeker, in Friesland. In March 1668 he entered the University of Leiden and that same year received his medical degree with a dissertation entitled De dolore intestinorum a flatu. The next year he published an essay on gout, Dissertatio de arthritide (Leiden, 1669), and a book on a text of Hippocratus, Meditationes in Hippocratis textum vigesimum quartum de veteri medicina (Leiden, 1669; 2nd ed. 1672).
In June 1673, then a physician in the employ of the Dutch East India Company, Ten Rhijne was sent to Batavia (now Jakarta, Indonesia) in the Ternaten, visiting the Cape on the way. The ship first entered Saldanha Bay on 13 October and proceeded to Table Bay two days later. It remained at the Cape until 10 November. During this time Ten Rhijne studied the Khoi and collected plants. His observations were later published in Schediasma de promontorio Bonae Spei, ejusque tractus incolis Hottentottis (A short account of the Cape of Good Hope and of the hottentots who inhabit the region; Schaffhausen, 1686). A reprint, with an English translation (Shapera & Farrington, 1933) was published by the Van Riebeeck Society. The book is mainly a description of the Khoi, based on his own observations, discussions with both Khoi and colonists, and the available literature. Among others he noted the westernisation and increasing loss of cultural identity among the Khoi living in contact with the settlers. The book contained little about the natural history of the colony, but included a list (in Latin) of the names of many of the mammals and birds to be found there.
Arriving in Batavia in January 1674 Ten Rhijne assumed his medical duties, which included giving lessons in anatomy to local surgeons. In June that year he was sent to the trading station on Decima, in the harbour of Nagasaki, Japan, in response to a request by the emperor of that country that the Dutch East India Company send out a qualified physician. During the two years he spent in Japan he visited the court at Jedo, and studied the tea plant, its cultivation and its effect on the human body. The results of these investigations, with descriptions and illustrations of the plants he had collected at the Cape, were published as "Excerpta ex observationibus Japonicis de fructice thee, cum fasciculo rariorum plantarum ab ipso in promontorio Bonae Spei et Sardanha sinu anno 1673 collectarum, atque demum ex India anno 1677 in Europam ad Jacobum Breynium transmissarum", in Jacob Breyne's Exoticarum plantarum centuria prima (Danzig, 1678). Included in this work are desriptions and illustrations of 48 Cape plants, and a catalogue of 85 species that Ten Rhijne recorded at the Cape. Some of his specimens ended up in the herbarium of the British Museum and in Oxford. According to Heniger (1986) he was the second most important botanist (after Paul Hermann*) to collect at the Cape up to the time of his visit.
Ten Rhijne was back in Batavia by December 1676 and in July 1677 became superintendent of the leper colony there. From October 1679 to November 1680 he spent most of his time on the west coast of Sumatra, where he investigated silver deposits. In March 1681 he became a member of the Council of Justice at Batavia, serving in this position until his death in 1700. On the basis of his knowledge of tropical plants Hendrik A. van Reede*, whom he met in Batavia in 1677, asked him to assist with the Latin descriptions and medicinal properties of plants for his Hortus Malabaricus, published in Amsterdam between 1679 and 1703. However, Ten Rhijne's most important work was a treatise on Asiatic leprosy, Verhandelingen van de Asiatise melaatsheid (Amsterdam, 1687), in which he gave a good description of the disease, its etiology, prevention and treatment. He also published a work on the flora and medicine (including acupuncture) of Japan, Dissertatio de arthritide, mantissa schematica de acupunctura, orationes tres de chymiae et botanicae antiquitate et dignitate, de physiognomia, et de monstris (London and The Hague, 1683, 2nd ed. Leipzig, 1890). Ten Rhijne was married twice, but had no children.